virtual bool FindExternalVisibleDeclsByName(const clang::DeclContext* DC,
                                                clang::DeclarationName Name) {
      if (m_Callbacks)
        return m_Callbacks->LookupObject(DC, Name);

      return false;
    }
    /// \brief Provides last resort lookup for failed unqualified lookups.
    ///
    /// This gets translated into InterpreterCallback's call.
    ///
    ///\param[out] R The recovered symbol.
    ///\param[in] S The scope in which the lookup failed.
    ///
    ///\returns true if a suitable declaration is found.
    ///
    virtual bool LookupUnqualified(clang::LookupResult& R, clang::Scope* S) {
      if (m_Callbacks) {
        return m_Callbacks->LookupObject(R, S);
      }

      return false;
    }
 virtual void CompleteType(TagDecl* Tag) {
   if (m_Callbacks)
     m_Callbacks->LookupObject(Tag);
 }