createVarNameContainer_() {
    const varNameContainer = document.createElement('div');
    varNameContainer.className = 'typedModalVariableInputContainer';

    const varNameLabel = document.createElement('label');
    varNameLabel.className = 'typedModalVariableLabel';
    varNameLabel.textContent =
      Blockly.Msg['TYPED_VAR_MODAL_VARIABLE_NAME_LABEL'];
    varNameLabel.setAttribute('for', 'variableInput');

    const varNameInput = document.createElement('input');
    varNameInput.className = 'typedModalVariableNameInput';
    varNameInput.type = 'text';
    varNameInput.id = 'variableInput';

    varNameContainer.appendChild(varNameLabel);
    varNameContainer.appendChild(varNameInput);
    return varNameContainer;
  }
Create the div that holds the text input and label for the variable name
input.
@returns {HTMLDivElement} The div holding the text input and label for text
    input.
@protected