Remove generic params from cache methods

It doesn't work to have a generic parameter on the method without also
providing that parameter to the method some how (i.e. as a class
parameter).

So in most cases it makes much more sense to simply accept Objects. In
the case of providing a ValueLoader, we can guarantee the return type.

Author: hinerm

src/main/java/org/scijava/cache/CacheService.java

@@ -47,13 +47,13 @@ public interface CacheService extends SciJavaService {
 	 * @param key A key.
 	 * @param value A value.
 	 */
-	<K, V> void put(K key, V value);
+	void put(Object key, Object value);
 
 	/**
 	 * @param key A key
 	 * @return The cached object, or null if the object is not in the cache.
 	 */
-	<K, V> V get(K key);
+	Object get(Object key);
 
 	/**
 	 * @param key A key
@@ -63,5 +63,5 @@ public interface CacheService extends SciJavaService {
 	 *         of the value loader.
 	 * @throws ExecutionException
 	 */
-	<K, V> V get(K key, Callable<V> valueLoader) throws ExecutionException;
+	<V> V get(Object key, Callable<V> valueLoader) throws ExecutionException;
 }

src/main/java/org/scijava/cache/DefaultCacheService.java

@@ -52,21 +52,21 @@ public class DefaultCacheService extends AbstractService implements
 	private Map<Object, Object> map;
 
 	@Override
-	public <K, V> void put(final K key, final V value) {
+	public void put(final Object key, final Object value) {
 		map.put(key, value);
 	}
 
-	@SuppressWarnings("unchecked")
 	@Override
-	public <K, V> V get(final K key) {
-		return (V) map.get(key);
+	public Object get(final Object key) {
+		return map.get(key);
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
-	public <K, V> V get(final K key, final Callable<V> valueLoader)
+	public <V> V get(final Object key, final Callable<V> valueLoader)
 		throws ExecutionException
 	{
-		return get(key);
+		return (V)get(key);
 	}
 
 	// -- Service Methods --