How to use the pyulog.core.ULog.SYNC_BYTES function in pyulog

from current location, else, from current location till end of file.
        return true if successful, else return false and seek back to initial position and
            set _has_sync to false if searched till end of file
        """
        sync_seq_found = False
        initial_file_position = self._file_handle.tell()
        current_file_position = initial_file_position

        search_chunk_size = 512 # number of bytes that are searched at once

        if last_n_bytes != -1:
            current_file_position = self._file_handle.seek(-last_n_bytes, 1)
            search_chunk_size = last_n_bytes

        chunk = self._file_handle.read(search_chunk_size)
        while len(chunk) >= len(ULog.SYNC_BYTES):
            current_file_position += len(chunk)
            chunk_index = chunk.find(ULog.SYNC_BYTES)
            if chunk_index >= 0:
                if self._debug:
                    print("Found sync at %i" % (current_file_position - len(chunk) + chunk_index))
                # seek to end of sync sequence and break
                current_file_position = self._file_handle.seek(current_file_position - len(chunk)\
                         + chunk_index + len(ULog.SYNC_BYTES), 0)
                sync_seq_found = True
                break

            elif last_n_bytes != -1:
                # we read the whole last_n_bytes and did not find sync
                break

            # seek back 7 bytes to handle boundary condition and read next chunk

set _has_sync to false if searched till end of file
        """
        sync_seq_found = False
        initial_file_position = self._file_handle.tell()
        current_file_position = initial_file_position

        search_chunk_size = 512 # number of bytes that are searched at once

        if last_n_bytes != -1:
            current_file_position = self._file_handle.seek(-last_n_bytes, 1)
            search_chunk_size = last_n_bytes

        chunk = self._file_handle.read(search_chunk_size)
        while len(chunk) >= len(ULog.SYNC_BYTES):
            current_file_position += len(chunk)
            chunk_index = chunk.find(ULog.SYNC_BYTES)
            if chunk_index >= 0:
                if self._debug:
                    print("Found sync at %i" % (current_file_position - len(chunk) + chunk_index))
                # seek to end of sync sequence and break
                current_file_position = self._file_handle.seek(current_file_position - len(chunk)\
                         + chunk_index + len(ULog.SYNC_BYTES), 0)
                sync_seq_found = True
                break

            elif last_n_bytes != -1:
                # we read the whole last_n_bytes and did not find sync
                break

            # seek back 7 bytes to handle boundary condition and read next chunk
            current_file_position = self._file_handle.seek(-(len(ULog.SYNC_BYTES)-1), 1)
            chunk = self._file_handle.read(search_chunk_size)