shadows/framework/src/main/java/org/robolectric/shadows/ShadowMediaCodec.java
@Implementation(minSdk = LOLLIPOP)
  protected ByteBuffer getBuffer(boolean input, int index) {
    ByteBuffer[] buffers = input ? inputBuffers : outputBuffers;

    return (index >= 0 && index < buffers.length) ? buffers[index] : null;
  }
@Implementation(minSdk = LOLLIPOP)
  protected ByteBuffer getBuffer(boolean input, int index) {
    ByteBuffer[] buffers = input ? inputBuffers : outputBuffers;

    return (index >= 0 && index < buffers.length) ? buffers[index] : null;
  }
Returns the input or output buffer corresponding to the given index, or null if invalid.