generate unique id's for each element.
refactor parser.
rename @data to @elements to avoid clash in names.
add method to find children of element.
add method to get data of id.
clean up tests
do a bunch of shit.
simplify the determination of parents/children.
allow pushing more than one line at a time.
make all tests pass for child/parent determination.
start writing tests for some valid json.
add some more checks.
fix error determining parent.
fix english in assertions.