child?()
Returns true is this is a child node
# File activerecord/lib/active_record/acts/nested_set.rb, line 127 def child? parent_id = self[parent_column] !(parent_id == 0 || parent_id.nil?) && (self[left_col_name] > 1) && (self[right_col_name] > self[left_col_name]) end