def typed_value_for(key, value)
      fields.key?(key) ? fields[key].mongoize(value) : value.mongoize
    end
def typed_value_for(key, value)
      fields.key?(key) ? fields[key].mongoize(value) : value.mongoize
    end
Return the typecasted value for a field.

 @example Get the value typecasted.
   person.typed_value_for(:title, :sir)

 @param [ String, Symbol ] key The field name.
 @param [ Object ] value The uncast value.

 @return [ Object ] The cast value.

 @since 1.0.0