Definition
/**
* Create a new COPY query builder for data import/export.
*
* Usage:
* copy()->from('users')->file('/tmp/users.csv')->format(CopyFormat::CSV)
* copy()->to('users')->file('/tmp/users.csv')->format(CopyFormat::CSV)
* copy()->toQuery(select(...))->file('/tmp/data.csv')
*/
copy() : CopyFactory