code: public boolean hasOutputVariable(String name) {
          for (OutputVariable outputVariable : this.outputVariables) {
              if (outputVariable.getName().equals(name)) {
                  return true;
              }
          }
          return false;
      }
docs: Indicates whether an output variable of the given name is in the output
  variables
  
  @param name is the name of the output variable
  @return whether an output variable is registered with the given name