code: public RawRequest header(String name, String value) {
          headers.put(name, value);
          setRequestConfigDirty();
          return this;
      }
docs: Set a header value for the underlying HTTP request.
  <p>
  Headers set with this method will take precedence over headers found in
  the configured {@link SdkRequestConfig}.
  
  @param name The name of the header.
  @param value The value of the header.
  
  @return This object for method chaining.