Creates a new buffer whose content is a merged copy of the specified
{@code buffers}' readable bytes. The new buffer's {@code readerIndex}
and {@code writerIndex} are {@code 0} and the sum of all buffers'
{@code readableBytes} respectively.
@throws IllegalArgumentException
if the specified buffers' endianness are different from each
other
Creates a new buffer whose content is a merged copy of the specified {@code buffers}' readable bytes. The new buffer's {@code readerIndex} and {@code writerIndex} are {@code 0} and the sum of all buffers' {@code readableBytes} respectively.
@throws IllegalArgumentException if the specified buffers' endianness are different from each other