code: public InputVariable removeInputVariable(String name) {
          for (Iterator<InputVariable> it = this.inputVariables.iterator(); it.hasNext();) {
              InputVariable inputVariable = it.next();
              if (inputVariable.getName().equals(name)) {
                  it.remove();
                  return inputVariable;
              }
          }
          throw new RuntimeException(String.format(
                  "[engine error] no input variable by name <%s>", name));
      }
docs: Removes the given input variable from the list of input variables.
  
  @param name is the name of the input variable
  @return the input variable of the given name
  @throws RuntimeException if there is no variable with the given name