If an attempt is made to reference a node in a context where it does not exist . [INDEX_SIZE_ERR] 
NOT_FOUND_ERR
H I E R A R C H Y _ R E Q U E S T _ E R R
W R O N G _ D O C U M E N T _ E R R
N O _ M O D I F I C A T I O N _ A L L O W E D _ E R R
N O T _ F O U N D _ E R R
N O T _ S U P P O R T E D _ E R R
I N V A L I D _ M O D I F I C A T I O N _ E R R
I N V A L I D _ A C C E S S _ E R R
T Y P E _ M I S M A T C H _ E R R