def digest_from_type(type)
      id = type.to_s.upcase
      instance = OpenSSL::Digest.const_get(id).new
    end
def digest_from_type(type)
      id = type.to_s.upcase
      instance = OpenSSL::Digest.const_get(id).new
    end
Create a new instance of the {Digest} class that corresponds to the given
 type.

 @param [#to_s] type
   the type of digest to use

 @return [~Digest]
   an instance of the digest class