def imported_file
    # WARNING : files under 10kb in size get treated as StringIO by OpenUri
    # http://stackoverflow.com/questions/10496874/why-does-openuri-treat-files-under-10kb-in-size-as-stringio
    OpenURI::Buffer.send :remove_const, 'StringMax' if OpenURI::Buffer.const_defined?('StringMax')
    OpenURI::Buffer.const_set 'StringMax', 0