### Question:
Paint { public String pyramid(int height) { return this.loopBy( height, 2 * height - 1, (row, column) -> row >= height - column - 1 && row + height - 1 >= column ); }  String rightTrl(int height); String leftTrl(int height); String pyramid(int height);  }### Answer:
@Test public void whenPyramidFive() { Paint paint = new Paint(); String rst = paint.pyramid(5); System.out.println(rst); assertThat(rst, is( new StringJoiner(System.lineSeparator(), "", System.lineSeparator()) .add(" ^ ") .add(" ^^^ ") .add(" ^^^^^ ") .add(" ^^^^^^^ ") .add("^^^^^^^^^") .toString() ) ); }