getKeyFromContext(ctx) {
		if (!this.opts.shardKey) return null;

		if (isFunction(this.opts.shardKey)) return this.opts.shardKey.call(this, ctx);

		if (this.opts.shardKey.startsWith("#")) return _.get(ctx.meta, this.opts.shardKey.slice(1));

		return _.get(ctx.params, this.opts.shardKey);
	}
Get key field value from Context.

@param {Context} ctx
@returns {any}
@memberof ShardStrategy