module ActiveModel::Validations::ClassMethods

def validators_on(*attributes)

# ]
# #,
# => [
Person.validators_on(:name)

end
validates_inclusion_of :age, in: 0..99
validates_presence_of :name

attr_accessor :name, :age

include ActiveModel::Validations
class Person

List all validators that are being used to validate a specific attribute. 
def validators_on(*attributes)
  attributes.flat_map do |attribute|
    _validators[attribute.to_sym]
  end
end