Input DataFrame: rowsCount = 7, columnsCount = 5

name		age	city	weight	isHappy
firstName	lastName
Alice	Cooper	15	London	54	true
Bob	Dylan	45	Dubai	87	true
Charlie	Daniels	20	Moscow	null	false
Charlie	Chaplin	40	Milan	null	true
Bob	Marley	30	Tokyo	68	true
Alice	Wolf	20	null	55	false
Charlie	Byrd	30	Moscow	90	true

Output DataFrame: rowsCount = 7, columnsCount = 5

name		age	city	weight	isHappy
lastName	firstName
Cooper	Alice	15	London	54	true
Dylan	Bob	45	Dubai	87	true
Daniels	Charlie	20	Moscow	null	false
Chaplin	Charlie	40	Milan	null	true
Marley	Bob	30	Tokyo	68	true
Wolf	Alice	20	null	55	false
Byrd	Charlie	30	Moscow	90	true