getButton (text, icon, title) {
    /* Prepare icon. */
    if (icon) {
      icon.classList.add('left')
      icon.style.marginRight = '5px'
    }

    /* Create and return button. */
    const el = super.getButton(text, icon, title)
    el.classList.add('waves-effect', 'waves-light', 'btn')
    el.style.fontSize = '0.75rem'
    el.style.height = '24px'
    el.style.lineHeight = '24px'
    el.style.marginLeft = '5px'
    el.style.padding = '0 0.5rem'
    return el
  }
Gets a single button element.

@param {string} text The button text.
@param {HTMLElement} icon The icon object.
@param {string} title The button title.
@returns {HTMLElement} The button object.
@see http://materializecss.com/buttons.html