<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def has_vtable(decl_type):
 """True, if class has virtual table, False otherwise"""

    assert isinstance(decl_type, class_declaration.class_t)
    return bool(
        decl_type.calldefs(
            lambda f: isinstance(f, calldef_members.member_function_t) and
            f.virtuality != calldef_types.VIRTUALITY_TYPES.NOT_VIRTUAL,
            recursive=False,
            allow_empty=True))