code: public ReportTaskProgressRequest withFields(Field... fields) {
          if (this.fields == null) {
              setFields(new com.amazonaws.internal.SdkInternalList<Field>(fields.length));
          }
          for (Field ele : fields) {
              this.fields.add(ele);
          }
          return this;
      }
docs: <p>
  Key-value pairs that define the properties of the ReportTaskProgressInput object.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setFields(java.util.Collection)} or {@link #withFields(java.util.Collection)} if you want to override the
  existing values.
  </p>
  
  @param fields
  Key-value pairs that define the properties of the ReportTaskProgressInput object.
  @return Returns a reference to this object so that method calls can be chained together.