### Question:
Paint { public String leftTrl(int height) { return this.loopBy( height, height, (row, column) -> row >= height - column - 1 ); }  String rightTrl(int height); String leftTrl(int height); String pyramid(int height);  }### Answer:
@Test public void whenPyramid4Left() { Paint paint = new Paint(); String rst = paint.leftTrl(4); System.out.println(rst); assertThat(rst, is( new StringJoiner(System.lineSeparator(), "", System.lineSeparator()) .add(" ^") .add(" ^^") .add(" ^^^") .add("^^^^") .toString() ) ); }