'Set a configuration variable to a specific value.
By using this method, you can override the normal lookup
process used in ``get_config_variable`` by explicitly setting
a value.  Subsequent calls to ``get_config_variable`` will
use the ``value``.  This gives you per-session specific
configuration values.
>>> # Assume logical name \'foo\' maps to env var \'FOO\'
>>> os.environ[\'FOO\'] = \'myvalue\'
>>> s.get_config_variable(\'foo\')
\'myvalue\'
>>> s.set_config_variable(\'foo\', \'othervalue\')
>>> s.get_config_variable(\'foo\')
\'othervalue\'
:type logical_name: str
:param logical_name: The logical name of the session variable
you want to set.  These are the keys in ``SESSION_VARIABLES``.
:param value: The value to associate with the config variable.'

def set_config_variable(self, logical_name, value):

    self._session_instance_vars[logical_name] = value
