docs: @SuppressWarnings("unused")
      private void allocateDataChannel(int channelType) {
          switch (channelType) {
              case NORMALS:
                  m_normals = ByteBuffer.allocateDirect(
                          m_numVertices * 3 * SIZEOF_FLOAT);
                  m_normals.order(ByteOrder.nativeOrder());
                  break;
              case TANGENTS:
                  m_tangents = ByteBuffer.allocateDirect(
                          m_numVertices * 3 * SIZEOF_FLOAT);
                  m_tangents.order(ByteOrder.nativeOrder());
                  break;
              default:
                  throw new IllegalArgumentException("unsupported channel type");
          }
      }