private String[] getMethodSignatures() throws Exception {
if (methodSignatureCache == null) {
SignatureFinder sigFinder = new SignatureFinder();
Set<String> sigs = new HashSet<String>();
for (String targetType : targetTypeNames) {
sigFinder.gatherConstructorSignatures(targetType, sigs);
}
methodSignatureCache = sigs.toArray(new String[sigs.size()]);
}
return methodSignatureCache;
}