def ecdsa_signature_normalize(raw_sig, check_only: false)
      sigout = check_only ? nil : C::ECDSASignature.new.pointer
      res = C.secp256k1_ecdsa_signature_normalize(@ctx, sigout, raw_sig)
      [res == 1, sigout]
    end
def ecdsa_signature_normalize(raw_sig, check_only: false)
      sigout = check_only ? nil : C::ECDSASignature.new.pointer
      res = C.secp256k1_ecdsa_signature_normalize(@ctx, sigout, raw_sig)
      [res == 1, sigout]
    end
Check and optionally convert a signature to a normalized lower-S form. If
 check_only is `true` then the normalized signature is not returned.

 This function always return a tuple containing a boolean (`true` if not
 previously normalized or `false` if signature was already normalized),
 and the normalized signature. When check_only is `true`, the normalized
 signature returned is always `nil`.