code: public GitlabHTTPRequestor with(String key, Object value) {
          if (value != null && key != null) {
              data.put(key, value);
          }
          return this;
      }
docs: Sets the HTTP Form Post parameters for the request
  Has a fluent api for method chaining
  
  @param key       Form parameter Key
  @param value     Form parameter Value
  @return this