import com.holonplatform.core.query.QueryFunction.Count; //导入依赖的package包/类
/**
 * Build an aggregation {@link FunctionExpression} on this property using the {@link Count} function, which returns
 * the count of the values of the property.
 * @return A {@link Count} expression on this property, expressed as a {@link Property} to allow inclusion in
 *         {@link PropertySet} and {@link PropertyBox} structures.
 */
default PathFunctionExpressionProperty<T, Long> count() {
	return PathFunctionExpressionProperty.create(Count.create(), this);
}
 

import com.holonplatform.core.query.QueryFunction.Count; //导入依赖的package包/类
/**
 * Create a function expression which represents the {@link Count} aggregation function on given <code>path</code>.
 * <p>
 * With the <em>count</em> aggregation function, the query expression and projection type is of {@link Long} type.
 * </p>
 * @param <T> Path type
 * @param path Path to which to apply the function
 * @return A new {@link PathFunctionExpression}
 */
static <T> PathFunctionExpression<T, Long> count(Path<T> path) {
	return PathFunctionExpressionProperty.create(Count.create(), path);
}