code: public Termination withCallingRegions(String... callingRegions) {
          if (this.callingRegions == null) {
              setCallingRegions(new java.util.ArrayList<String>(callingRegions.length));
          }
          for (String ele : callingRegions) {
              this.callingRegions.add(ele);
          }
          return this;
      }
docs: <p>
  The countries to which calls are allowed.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setCallingRegions(java.util.Collection)} or {@link #withCallingRegions(java.util.Collection)} if you want
  to override the existing values.
  </p>
  
  @param callingRegions
  The countries to which calls are allowed.
  @return Returns a reference to this object so that method calls can be chained together.