code: public CreateFunctionDefinitionVersionRequest withFunctions(Function... functions) {
          if (this.functions == null) {
              setFunctions(new java.util.ArrayList<Function>(functions.length));
          }
          for (Function ele : functions) {
              this.functions.add(ele);
          }
          return this;
      }
docs: A list of Lambda functions in this function definition version.
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setFunctions(java.util.Collection)} or {@link #withFunctions(java.util.Collection)} if you want to
  override the existing values.
  </p>
  
  @param functions
  A list of Lambda functions in this function definition version.
  @return Returns a reference to this object so that method calls can be chained together.