@property<EOL><INDENT>def virt_env(self):<DEDENT>
if self._virt_env is None:<EOL><INDENT>self._virt_env = self._create_virt_env()<EOL><DEDENT>return self._virt_env<EOL>
Getter for this instance's virt env, creates it if needed

Returns:
    lago.virt.VirtEnv: virt env instance used by this prefix