# File lib/grape/validations/types/file.rb, line 18
        def value_coerced?(value)
          # Rack::Request creates a Hash with filename,
          # content type and an IO object. Do a bit of basic
          # duck-typing.
          value.is_a?(::Hash) && value.key?(:tempfile) && value[:tempfile].is_a?(Tempfile)
        end