You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: field.rb
    path of file: ./repos/manageiq/lib/miq_expression
    
    the code of the file until where you have to start completion: class MiqExpression::Field < MiqExpression::Target
  REGEX = /
\A
(?<model_name>(?>[[:upper:]][[:alnum:]]+(?:::[[:upper:]][[:alnum:]]+)*))
(?!.*
    
  def valid?
    (target < ApplicationRecord) &&
      (target.column_names.include?(column) || virtual_attribute? || custom_attribute_column?)
  rescue ArgumentError
    # the association chain is not legal, so no, it not valid
    false
  end