+/* Handly macro for suppressing unreferenced-parameter compiler warnings. */
+#ifndef UNUSED
+#define UNUSED(x) (void)(x)
+#endif
+
+/* Number of required fields to keep track of
+ * (change here or on compiler command line). */
+#ifndef PB_MAX_REQUIRED_FIELDS
+#define PB_MAX_REQUIRED_FIELDS 64
+#endif
+