initConstants () {
    super.initConstants()

    this.constants.classes.buttonsGroup = 'button-group'
    this.constants.classes.buttonsDropdown = ''
    this.constants.classes.input = 'input-field'
    this.constants.classes.input = ''
    this.constants.classes.paginationDropdown = ''
    this.constants.classes.buttonActive = 'green'

    this.constants.html.toolbarDropdown = ['<ul class="dropdown-content">', '</ul>']
    this.constants.html.toolbarDropdownItem = '<li class="dropdown-item-marker"><label>%s</label></li>'
    this.constants.html.toolbarDropdownSeparator = '<li class="divider" tabindex="-1"></li>'
    this.constants.html.pageDropdown = ['<ul id="pagination-list-id" class="dropdown-content">', '</ul>']
    this.constants.html.pageDropdownItem = '<li><a class="%s" href="#">%s</a></li>'
    this.constants.html.dropdownCaret = '<i class="material-icons">arrow_drop_down</i>'
    this.constants.html.pagination = ['<ul class="pagination%s">', '</ul>']
    this.constants.html.paginationItem = '<li class="waves-effect page-item%s" aria-label="%s"><a href="#">%s</a></li>'
    this.constants.html.icon = '<i class="%s">%s</i>'
    this.constants.html.inputGroup = '%s%s'
  }
@author zhixin wen <wenzhixin2010@gmail.com>
https://github.com/wenzhixin/bootstrap-table/
theme: https://materializecss.com/