def _set_options(self, qobj_config=None, backend_options=None):
<EOL>self._initial_statevector = self.DEFAULT_OPTIONS["<STR_LIT>"]<EOL>self._chop_threshold = self.DEFAULT_OPTIONS["<STR_LIT>"]<EOL>if backend_options is None:<EOL><INDENT>backend_options = {}<EOL><DEDENT>if '<STR_LIT>' in backend_options:<EOL><INDENT>self._initial_statevector = np.array(backend_options['<STR_LIT>'],<EOL>dtype=complex)<EOL><DEDENT>elif hasattr(qobj_config, '<STR_LIT>'):<EOL><INDENT>self._initial_statevector = np.array(qobj_config.initial_statevector,<EOL>dtype=complex)<EOL><DEDENT>if self._initial_statevector is not None:<EOL><INDENT>norm = np.linalg.norm(self._initial_statevector)<EOL>if round(norm, <NUM_LIT:12>) != <NUM_LIT:1>:<EOL><INDENT>raise BasicAerError('<STR_LIT>' +<EOL>'<STR_LIT>'.format(norm))<EOL><DEDENT><DEDENT>if '<STR_LIT>' in backend_options:<EOL><INDENT>self._chop_threshold = backend_options['<STR_LIT>']<EOL><DEDENT>elif hasattr(qobj_config, '<STR_LIT>'):<EOL><INDENT>self._chop_threshold = qobj_config.chop_threshold<EOL><DEDENT>
Set the backend options for all experiments in a qobj