function isInside(inner, outer) {
			return (
				inner.range[0] >= outer.range[0] &&
				inner.range[1] <= outer.range[1]
			);
		}
Checks the position of given nodes.
@param {ASTNode} inner A node which is expected as inside.
@param {ASTNode} outer A node which is expected as outside.
@returns {boolean} `true` if the `inner` node exists in the `outer` node.
@private