def calc_sha(self, checksum):
with LogTask('<STR_LIT>'.format(checksum)):<EOL><INDENT>with open(self.dst + '<STR_LIT>', '<STR_LIT>') as f:<EOL><INDENT>sha = utils.get_hash(self.dst, checksum)<EOL>f.write(sha)<EOL><DEDENT>self.exported_metadata[checksum] = sha<EOL><DEDENT>
Calculate the checksum of the new exported disk, write it to
a file, and update this managers 'exported_metadata'.

Args:
    checksum(str): The type of the checksum