begin(cap) {
        return cap ? this._inner.capBegin : this._inner.begin;
    }
@method txMode.TransactionMode#begin
@description
Returns a complete BEGIN statement, according to all the parameters passed into the class.

This method is primarily for internal use by the library.

@param {boolean} [cap=false]
Indicates whether the returned SQL must be capitalized.

@returns {string}