a.insertText("Hello ", 0);
harness.check(a.getText(), "Hello World");
// Insert at the end of text.
harness.check(a.getPeer(), null);
a.insertText("!", a.getText().length());
harness.check(a.getText(), "Hello World!");
// Insert in the middle of text.
harness.check(a.getPeer(), null);
a.insertText(" There", 5);