code: function insert() {
      var insertValues = this.single.insert || [];
      var sql = 'insert into ' + this.tableName + ' ';
  
      if (Array.isArray(insertValues)) {
        if (insertValues.length === 0) {
          return '';
        }
      } else if (typeof insertValues === 'object' && isEmpty(insertValues)) {
        return sql + this._emptyInsertValue;
      }
  
      var insertData = this._prepInsert(insertValues);
      this.__insertValues = insertData.values;
      if (typeof insertData === 'string') {
        sql += insertData;
      } else {
        if (insertData.columns.length) {
          sql += '(' + this.formatter.columnize(insertData.columns);
          sql += ') values (';
          sql += this.formatter.parameterize(insertData.columns);
          sql += ')';
        } else if (insertValues.length === 1 && insertValues[0]) {
          sql += this._emptyInsertValue;
        } else {
          sql = '';
        }
      }
      var out = {
        sql: sql,
        bindings: insertData.values
      };
      if (out.sql !== '') {
        out.returning = this.single.returning;
      }
      return out;
    }
docs: Compiles an "insert" query, allowing for multiple inserts using a single query statement.