class RailsBestPractices::Reviews::IsolateSeedDataReview

def remember_new_variable(node)

then remember the left value as new variable.
if the right vavlue is a method_add_arg node with message "new",
check assignment node, 
def remember_new_variable(node)
  right_value = node.right_value
  if right_value.sexp_type == :method_add_arg && right_value.message.to_s == 'new'
    @new_variables << node.left_value.to_s
  end
end