# File lib/brakeman/checks/check_redirect.rb, line 146
  def explicit_host? arg
    return unless sexp? arg

    if hash? arg
      if value = hash_access(arg, :host)
        return !has_immediate_user_input?(value)
      end
    elsif call? arg
      target = arg.target

      if hash? target and value = hash_access(target, :host)
        return !has_immediate_user_input?(value)
      elsif call? arg
        return explicit_host? target
      end
    end

    false
  end