Complete the TODO in below code: public Tuple lookup$($Object key$)\{$

String keyColumnName $=$ schema.getKey$()$;

if $($keyColumnName $==$ null$)$ throw new RuntimeException$("$Cannot lookup by key when schema does not have a key."$)$;

$//$TODO

$//$ find the row with the given key value

throw new UnsupportedOperationException$()$;

$\}$

@Override

public ITable lookup$($String colname, Object value$)\{$

ITable result $=$ new Table$($schema$)$;

$//$ TODO

$//$ find all rows with the given column value

$//$ insert the row into result table and return

throw new UnsupportedOperationException$()$;

$\}$