test suite test string writer
test case basic test()
the writer : string writer • new()
assert the writer • size() == 0
assert the writer • elements() == ""
the writer • write all("foo")
assert the writer • size() == 3
assert the writer • elements() == "foo"
the writer • write('b')
the writer • write('a')
the writer • write('r')
assert the writer • size() == 6
assert the writer • elements() == "foobar"
the writer • clear()
please assert elements == "foobar"please assert the writer • size() == 0please assert the writer • elements() == ""