public static bool TryCreateFromCompact(ReadOnlySpan <byte> in64, int recid, out SecpRecoverableECDSASignature?sig)
 {
     sig = null;
     if (SecpECDSASignature.TryCreateFromCompact(in64, out var compact) && compact is SecpECDSASignature)
     {
         sig = new SecpRecoverableECDSASignature(compact, recid);
         return(true);
     }
     return(false);
 }
 public SecpRecoverableECDSASignature(SecpECDSASignature sig, int recid)
 {
     if (sig == null)
     {
         throw new ArgumentNullException(nameof(sig));
     }
     this.r     = sig.r;
     this.s     = sig.s;
     this.recid = recid;
 }