/// <summary>
/// Takes an expression tree node and returns if the node is a variable node type.
/// </summary>
/// <param name="node">Expression tree node.</param>
/// <returns>Bool that represents is the node is a constant or variable node type.</returns>
private bool IsVariableNode(ExpressionTreeNode node)
{
Type nodeType = node.GetType();
return(nodeType.Equals(typeof(VariableNode)));
}
/// <summary>
/// Takes an expression tree node and returns if the node is a constant node type.
/// </summary>
/// <param name="node">Expression tree node.</param>
/// <returns>Bool that represents is the node is a constant or variable node type.</returns>
private bool IsConstantNode(ExpressionTreeNode node)
{
Type nodeType = node.GetType();
return(nodeType.Equals(typeof(ConstantNode)));
}