old_contents: import Mesh from './Mesh'
  
  export default
  class Box extends Mesh {
      static get defaultElementName() { return 'i-box' }
      static get _Class() { return Box }
  
      static get defaultBehaviors() {
          return {
              'box-geometry': initialBehaviors => {
                  return !initialBehaviors.some( b => b.endsWith( '-geometry' ) )
              },
              'phong-material': initialBehaviors => {
                  return !initialBehaviors.some( b => b.endsWith( '-material' ) )
              },
          }
      }
  }
  
new_contents: import Class from 'lowclass'
  import {native} from 'lowclass/native'
  import Mesh from './Mesh'
  
  export default
  Class('Box').extends( native(Mesh), {
      static: {
          defaultElementName: 'i-box',
  
          defaultBehaviors: {
              'box-geometry': initialBehaviors => {
                  return !initialBehaviors.some( b => b.endsWith( '-geometry' ) )
              },
              'phong-material': initialBehaviors => {
                  return !initialBehaviors.some( b => b.endsWith( '-material' ) )
              },
          },
      },
  })
  
subject: convert Box to lowclass