code: public ListPartsResult withParts(PartListElement... parts) {
          if (this.parts == null) {
              setParts(new java.util.ArrayList<PartListElement>(parts.length));
          }
          for (PartListElement ele : parts) {
              this.parts.add(ele);
          }
          return this;
      }
docs: <p>
  A list of the part sizes of the multipart upload. Each object in the array contains a <code>RangeBytes</code> and
  <code>sha256-tree-hash</code> name/value pair.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setParts(java.util.Collection)} or {@link #withParts(java.util.Collection)} if you want to override the
  existing values.
  </p>
  
  @param parts
  A list of the part sizes of the multipart upload. Each object in the array contains a
  <code>RangeBytes</code> and <code>sha256-tree-hash</code> name/value pair.
  @return Returns a reference to this object so that method calls can be chained together.