"message M1 {\n" +
" required string a = 1;\n" +
" message M1 { required string a = 1; }\n"+
"}\n";
FileDescriptorSource fileDescriptorSource = new FileDescriptorSource();
fileDescriptorSource.addProtoFile("file1.proto", file1);
Map<String, FileDescriptor> descriptors = parseAndResolve(fileDescriptorSource);
assertEquals(1, descriptors.size());
assertTrue(descriptors.containsKey("file1.proto"));
FileDescriptor fd = descriptors.get("file1.proto");