aeron-client/src/main/java/io/aeron/ImageFragmentAssembler.java
public void onFragment(final DirectBuffer buffer, final int offset, final int length, final Header header)
    {
        final byte flags = header.flags();

        if ((flags & UNFRAGMENTED) == UNFRAGMENTED)
        {
            delegate.onFragment(buffer, offset, length, header);
        }
        else
        {
            handleFragment(buffer, offset, length, header, flags);
        }
    }
public void onFragment(final DirectBuffer buffer, final int offset, final int length, final Header header)
    {
        final byte flags = header.flags();

        if ((flags & UNFRAGMENTED) == UNFRAGMENTED)
        {
            delegate.onFragment(buffer, offset, length, header);
        }
        else
        {
            handleFragment(buffer, offset, length, header, flags);
        }
    }
The implementation of {@link FragmentHandler} that reassembles and forwards whole messages.

@param buffer containing the data.
@param offset at which the data begins.
@param length of the data in bytes.
@param header representing the meta data for the data.