ExpressionParsing::EmptyVectorAccessor Node1 ExpressionParsing:: EmptyVectorAccessor + variableType() + loadInt() + loadDouble() + loadVecInt() + loadVec() - throwEmptyVector() Node2 ExpressionParsing:: IAccessor + ~IAccessor() + variableType() + loadInt() + loadDouble() + loadVecInt() + loadVec() Node2->Node1