public JoinDefinition(JoinSide left, JoinSide right, JoinType type)
{
left.GuardAgainstNull(nameof(left));
right.GuardAgainstNull(nameof(right));
Left = left;
Right = right;
Type = type;
}
internal void AddJoin(JoinSide left, JoinSide right, JoinType type)
{
Join = new JoinDefinition(left, right, type);
}