headersConsumer);
		/**
		 * Set the list of acceptable {@linkplain MediaType media types}, as
		 * specified by the {@code Accept} header.
		 * @param acceptableMediaTypes the acceptable media types
		 */
		B accept(MediaType... acceptableMediaTypes);
		/**
		 * Set the list of acceptable {@linkplain Charset charsets}, as specified
		 * by the {@code Accept-Charset} header.
		 * @param acceptableCharsets the acceptable charsets
		 */
		B acceptCharset(Charset... acceptableCharsets);
		/**
		 * Set the value of the {@code If-Modified-Since} header.
		 * @param ifModifiedSince the new value of the header
		 * @since 5.1.4
		 */
		B ifModifiedSince(ZonedDateTime ifModifiedSince);
		/**
		 * Set the value of the {@code If-Modified-Since} header.
		 * @param ifModifiedSince the new value of the header
		 * @since 5.1.4
		 */
		B ifModifiedSince(Instant ifModifiedSince);
		/**
		 * Set the value of the {@code If-Modified-Since} header.
		 * The date should be specified as the number of milliseconds since
		 * January 1, 1970 GMT.
		 * @param ifModifiedSince the new value of the header
		 */
		B ifModifiedSince(long ifModifiedSince);
		/**
		 * Set the values of the {@code If-None-Match} header.
		 * @param ifNoneMatches the new value of the header
		 */
		B ifNoneMatch(String... ifNoneMatches);
		/**
		 * Builds the request entity with no body.
		 * @return the request entity
		 * @see BodyBuilder#body(Object)
		 */
		RequestEntity build();
	}
	/**
	 * Defines a builder that adds a body to the response entity.
	 */
	public interface BodyBuilder extends HeadersBuilder {
		/**
		 * Set the length of the body in bytes, as specified by the
		 * {@code Content-Length} header.
		 * @param contentLength the content length
		 * @return this builder
		 * @see HttpHeaders#setContentLength(long)
		 */
		BodyBuilder contentLength(long contentLength);
		/**
		 * Set the {@linkplain MediaType media type} of the body, as specified
		 * by the {@code Content-Type} header.
		 * @param contentType the content type
		 * @return this builder
		 * @see HttpHeaders#setContentType(MediaType)
		 */
		BodyBuilder contentType(MediaType contentType);
		/**
		 * Set the body of the request entity and build the RequestEntity.
		 * @param  the type of the body
		 * @param body the body of the request entity
		 * @return the built request entity
		 */
		 RequestEntity body(T body);
		/**
		 * Set the body and type of the request entity and build the RequestEntity.
		 * @param  the type of the body
		 * @param body the body of the request entity
		 * @param type the type of the body, useful for generic type resolution
		 * @return the built request entity
		 * @since 4.3
		 */
		 RequestEntity body(T body, Type type);
	}
	private static class DefaultBodyBuilder implements BodyBuilder {
		private final HttpMethod method;
		private final HttpHeaders headers = new HttpHeaders();
		@Nullable
		private final URI uri;
		@Nullable
		private final String uriTemplate;
		@Nullable
		private final Object[] uriVarsArray;
		@Nullable
		private final Map uriVarsMap;
		DefaultBodyBuilder(HttpMethod method, URI url) {
			this.method = method;
			this.uri = url;
			this.uriTemplate = null;
			this.uriVarsArray = null;
			this.uriVarsMap = null;
		}
		DefaultBodyBuilder(HttpMethod method, String uriTemplate, Object... uriVars) {
			this.method = method;
			this.uri = null;
			this.uriTemplate = uriTemplate;
			this.uriVarsArray = uriVars;
			this.uriVarsMap = null;
		}
		DefaultBodyBuilder(HttpMethod method, String uriTemplate, Map uriVars) {
			this.method = method;
			this.uri = null;
			this.uriTemplate = uriTemplate;
			this.uriVarsArray = null;
			this.uriVarsMap = uriVars;
		}
		@Override
		public BodyBuilder header(String headerName, String... headerValues) {
			for (String headerValue : headerValues) {
				this.headers.add(headerName, headerValue);
			}
			return this;
		}
		@Override
		public BodyBuilder headers(@Nullable HttpHeaders headers) {
			if (headers != null) {
				this.headers.putAll(headers);
			}
			return this;
		}
		@Override
		public BodyBuilder headers(Consumer headersConsumer) {
			headersConsumer.accept(this.headers);
			return this;
		}
		@Override
		public BodyBuilder accept(MediaType... acceptableMediaTypes) {
			this.headers.setAccept(Arrays.asList(acceptableMediaTypes));
			return this;
		}
		@Override
		public BodyBuilder acceptCharset(Charset... acceptableCharsets) {
			this.headers.setAcceptCharset(Arrays.asList(acceptableCharsets));
			return this;
		}
		@Override
		public BodyBuilder contentLength(long contentLength) {
			this.headers.setContentLength(contentLength);
			return this;
		}
		@Override
		public BodyBuilder contentType(MediaType contentType) {
			this.headers.setContentType(contentType);
			return this;
		}
		@Override
		public BodyBuilder ifModifiedSince(ZonedDateTime ifModifiedSince) {
			this.headers.setIfModifiedSince(ifModifiedSince);
			return this;
		}
		@Override
		public BodyBuilder ifModifiedSince(Instant ifModifiedSince) {
			this.headers.setIfModifiedSince(ifModifiedSince);
			return this;
		}
		@Override
		public BodyBuilder ifModifiedSince(long ifModifiedSince) {
			this.headers.setIfModifiedSince(ifModifiedSince);
			return this;
		}
		@Override
		public BodyBuilder ifNoneMatch(String... ifNoneMatches) {
			this.headers.setIfNoneMatch(Arrays.asList(ifNoneMatches));
			return this;
		}
		@Override
		public RequestEntity build() {
			return buildInternal(null, null);
		}
		@Override
		public  RequestEntity body(T body) {
			return buildInternal(body, null);
		}
		@Override
		public  RequestEntity body(T body, Type type) {
			return buildInternal(body, type);
		}
		private  RequestEntity buildInternal(@Nullable T body, @Nullable Type type) {
			if (this.uri != null) {
				return new RequestEntity<>(body, this.headers, this.method, this.uri, type);
			}
			else if (this.uriTemplate != null){
				return new UriTemplateRequestEntity<>(body, this.headers, this.method, type,
						this.uriTemplate, this.uriVarsArray, this.uriVarsMap);
			}
			else {
				throw new IllegalStateException("Neither URI nor URI template");
			}
		}
	}
	/**
	 * RequestEntity initialized with a URI template and variables instead of a {@link URI}.
	 * @since 5.3
	 * @param  the body type
	 */
	public static class UriTemplateRequestEntity extends RequestEntity {
		private final String uriTemplate;
		@Nullable
		private final Object[] uriVarsArray;
		@Nullable
		private final Map uriVarsMap;
		UriTemplateRequestEntity(
				@Nullable T body, @Nullable MultiValueMap headers,
				@Nullable HttpMethod method, @Nullable Type type, String uriTemplate,
				@Nullable Object[] uriVarsArray, @Nullable Map uriVarsMap) {
			super(body, headers, method, null, type);
			this.uriTemplate = uriTemplate;
			this.uriVarsArray = uriVarsArray;
			this.uriVarsMap = uriVarsMap;
		}
		public String getUriTemplate() {
			return this.uriTemplate;
		}
		@Nullable
		public Object[] getVars() {
			return this.uriVarsArray;
		}
		@Nullable
		public Map getVarsMap() {
			return this.uriVarsMap;
		}
		@Override
		public boolean equals(@Nullable Object other) {
			if (this == other) {
				return true;
			}
			if (!super.equals(other)) {
				return false;
			}
			UriTemplateRequestEntity> otherEntity = (UriTemplateRequestEntity>) other;
			return (ObjectUtils.nullSafeEquals(this.uriTemplate, otherEntity.uriTemplate) &&
					ObjectUtils.nullSafeEquals(this.uriVarsArray, otherEntity.uriVarsArray) &&
					ObjectUtils.nullSafeEquals(this.uriVarsMap, otherEntity.uriVarsMap));
		}
		@Override
		public int hashCode() {
			return (29 * super.hashCode() + ObjectUtils.nullSafeHashCode(this.uriTemplate));
		}
		@Override
		public String toString() {
			return format(getMethod(), getUriTemplate(), getBody(), getHeaders());
		}
	}
}