For these XMLTable steps, use the dom$4$j API which is dependency managed by Maven $($as in step A$\text{'}).$

K$\text{'}$ A public put method which takes a key parameter $($string$),$ then a list of fields parameter $($list of objects$).$

$1$ If the degree of the given row doesn$$t match the result of calling the degree method, throw an illegal argument exception.

$2$ Linear search the row elements under the rows element to find a row with the given key.

$3$ On a hit, remove the old row element at the key under the rows element, put the new row element as suitable at the key

under the rows element, call flush, and return the old list of fields.

$4$ On a miss, put the new row element at the key under the rows element, call flush, and return null.

L$\text{'}$ A public get method which takes a key parameter.

$1$ Linear search the row elements under the rows element to find a row with the given key.

$2$ On a hit, return the old list of fields of the row element at the key under the rows element.

$3$ On a miss, return null.

M$\text{'}$ A public remove method which takes a key parameter.

$1$ Linear search the row elements under the rows element to find a row with the given key.

$2$ On a hit, remove the old row element at the key under the rows element, call flush, and return the old list of fields.

$3$ On a miss, return null.