RESOLVED - BATCH-728: Add remove(key) method to ExecutionContext class

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/ExecutionContext.java

@@ -280,6 +280,15 @@ public class ExecutionContext implements Serializable {
 		return map.containsKey(key);
 	}
 
+	/**
+	 * Removes the mapping for a key from this context if it is present.
+	 * 
+	 * @see java.util.Map#remove(Object)
+	 */
+	public Object remove(String key) {
+		return map.remove(key);
+	}
+
 	/**
 	 * Indicates whether or not a value is represented in this context.
 	 *