How to use the justext.utils.is_blank function in jusText

def test_string_with_chars_is_not_blank(self):
        assert not is_blank("  #  ")

def test_empty_string_is_blank(self):
        assert is_blank("")

def test_string_with_space_is_blank(self):
        assert is_blank(" ")

def test_string_with_narrow_nobreak_space_is_blank(self):
        assert is_blank("\u202F \t")

def test_string_with_nobreak_space_is_blank(self):
        assert is_blank("\u00A0\t ")

def test_string_with_whitespace_is_blank(self):
        assert is_blank("\t\n ")

def test_string_with_tab_is_blank(self):
        assert is_blank("\t")

def test_string_with_spaces_is_blank(self):
        assert is_blank("    ")

def test_string_with_newline_is_blank(self):
        assert is_blank("\n")

def characters(self, content):
        if is_blank(content):
            return

        text = self.paragraph.append_text(content)

        if self.link:
            self.paragraph.chars_count_in_links += len(text)
        self.br = False