<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _readFile(self, fileName):
 """ Returns the bytes of the file. """

        with open(fileName, 'rb') as binFile:
            b = binFile.read()
            return to_ubyte_array(b)