find(query) {
    const result = [];
    for (let i = 0, l = this.data.length; i < l; i += 1) {
      const row = this.data[i];
      if (this.match(row, query)) {
        result.push({ ...row });
      }
    }
    return result;
  }
Given a query, find the rows that match the given query
@param {Objet} query Query for the match.
@returns {Object[]} Rows that match the query, cloned.