_createIndexMap(indicesForReshaped) {
    if (this.indexMaps) {
      return
    }

    const indices = new Tensor(indicesForReshaped.data, indicesForReshaped.shape, { type: Int32Array })

    this.indexMaps = []

    const timesteps = this.inputShape[0]
    const sliceShape = this.inputShape.slice(1)
    for (let t = 0; t < timesteps; t++) {
      const sliceIndices = new Tensor([], sliceShape, { type: Int32Array })
      ops.assign(sliceIndices.tensor, indices.tensor.pick(t, ...Array(sliceShape.length).fill(null)))
      sliceIndices.reshapeTo2DSquare()
      sliceIndices.createGLTexture({ type: '2d', format: 'int' })
      this.indexMaps.push(sliceIndices)
    }
  }
Creates row/col index mappings to map input texture to time-distributed slices

@param {Object} indicesForReshaped