@Override public LevelConstraint getSigningCertificateIssuerSerialMatchConstraint(Context context) { SignatureConstraints mainSignature = getSignatureConstraintsByContext(context); if (mainSignature != null) { SignedAttributesConstraints signedAttributeConstraints = mainSignature.getSignedAttributes(); if (signedAttributeConstraints != null) { return signedAttributeConstraints.getIssuerSerialMatch(); } } return null; }