code: public UniqueProblem withProblems(Problem... problems) {
          if (this.problems == null) {
              setProblems(new java.util.ArrayList<Problem>(problems.length));
          }
          for (Problem ele : problems) {
              this.problems.add(ele);
          }
          return this;
      }
docs: <p>
  Information about the problems.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setProblems(java.util.Collection)} or {@link #withProblems(java.util.Collection)} if you want to override
  the existing values.
  </p>
  
  @param problems
  Information about the problems.
  @return Returns a reference to this object so that method calls can be chained together.