text: 
  const defaultMapping = { collapse: '', expand: '', 'delete': '', edit: '', add: '', cancel: '', save: '', moveup: '', movedown: '' }
  
  export class AbstractIconLib {
    constructor(icon_prefix = '', mapping = defaultMapping) {
      this.mapping = mapping
      this.icon_prefix = icon_prefix
    }
  
    getIconClass(key) {
      return this.mapping[key] ? this.icon_prefix + this.mapping[key] : null
    }
  
    getIcon(key) {
      const iconclass = this.getIconClass(key)
  
      if (!iconclass) return null
  
      const i = document.createElement('i')
      i.classList.add(...iconclass.split(' '))
  
      return i
    }
  }
  