@Override
    protected final boolean equalsExpression(ExpressionNode obj) {
        FunctionNode rhs = (FunctionNode)obj;
        if (!equals(result, rhs.result)) {
            return false;
        }
        if (!equalsFunction(rhs)) {
            return false;
        }
        return true;
    }
This abstract expression node represents a function to execute.

@author baldersheim
@author Simon Thoresen Hult
searchlib/src/main/java/com/yahoo/searchlib/expression/FunctionNode.java