code: public void wrap(final long offset, final long length)
      {
          if (offset == addressOffset && length == capacity)
          {
              return;
          }
  
          wrap(fileChannel, offset, length);
      }
docs: Remap the buffer using the existing file based on a new offset and length
  
  @param offset the offset of the file to start the mapping
  @param length of the buffer from the given address