<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def is_function_variadic(self):
 """Determine whether this function Type is a variadic function type."""

        assert self.kind == TypeKind.FUNCTIONPROTO

        return conf.lib.clang_isFunctionTypeVariadic(self)