function GLTFTextureBasisUExtension(parser) {
  this.parser = parser
  this.name = EXTENSIONS.KHR_TEXTURE_BASISU
}
BasisU Texture Extension

Specification: https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Khronos/KHR_texture_basisu
(draft PR https://github.com/KhronosGroup/glTF/pull/1751)