def constant(name, value = name)
      value = value.freeze rescue value
      define_method(name) { value }
    end
def constant(name, value = name)
      value = value.freeze rescue value
      define_method(name) { value }
    end
Create a constant named _name_, that refers to value _value_. _value is
 frozen, if this is possible. If you want to modify/exchange a value use
 DSLAccessor#dsl_reader/DSLAccessor#dsl_accessor instead.