How to use the mson/lib/fields.TextField function in mson

_create(props) {
    super._create(props);

    this.set({
      fields: [
        new TextField({
          name: 'firstName',
          label: 'First Name',
          required: true,
          block: false
        }),
        new TextField({ name: 'lastName', label: 'Last Name', required: true }),
        new EmailField({ name: 'email', label: 'Email' }),
        new ButtonField({
          name: 'import',
          label: 'Import',
          icon: 'ImportContacts'
        }),
        new ButtonField({
          name: 'submit',
          label: 'Submit',
          type: 'submit',
          icon: 'Save'
        }),
        new ButtonField({ name: 'cancel', label: 'Cancel', icon: 'Cancel' })
      ]
    });