snaker-core/src/main/java/org/snaker/engine/impl/SimpleContext.java
public <T> T findByName(String name, Class<T> clazz) {
		for (Entry<String, Object> entry : contextMap.entrySet()) {
			if (entry.getKey().equals(name) && clazz.isInstance(entry.getValue())) {
				return clazz.cast(entry.getValue());
			}
		}
		return null;
	}
public <T> T findByName(String name, Class<T> clazz) {
		for (Entry<String, Object> entry : contextMap.entrySet()) {
			if (entry.getKey().equals(name) && clazz.isInstance(entry.getValue())) {
				return clazz.cast(entry.getValue());
			}
		}
		return null;
	}
对外部提供的查找对象方法，根据名称、class类型查找
@param name
@param clazz
@return