Add ClassSource.attemptLoadFrom method

This method is an alternative to chaining retry calls

ProtocolLib/src/main/java/com/comphenix/protocol/utility/ClassSource.java

@@ -58,6 +58,19 @@ public abstract class ClassSource {
 		};
 	}
 
+	/**
+	 * Retrieve a class source that will attempt lookups in each of the given sources in the order they are in the array, and return the first value that is found.
+	 * @param sources - the class sources.
+	 * @return A new class source.
+	 */
+	public static ClassSource attemptLoadFrom(final ClassSource... sources) {
+		ClassSource source = sources[0];
+		for(int i = 1; i < sources.length; i++){
+			source = source.retry(sources[i]);
+		}
+		return source;
+	}
+
 	/**
 	 * Retrieve a class source that will retry failed lookups in the given source.
 	 * @param other - the other class source.