parse() {
		this.runHook('before-all');
		const nodes = this.gobbleExpressions();

		// If there's only one expression just try returning the expression
		const node = nodes.length === 1
		  ? nodes[0]
			: {
				type: Jsep.COMPOUND,
				body: nodes
			};
		return this.runHook('after-all', node);
	}
Top-level method to parse all expressions and returns compound or single node
@returns {jsep.Expression}