text: var tape = require("tape"),
      mat2 = require("..");
  
  
  tape("mat2.equal(a, b)", function(assert) {
      assert.equals(mat2.equals(mat2.create(), mat2.create()), true);
      assert.end();
  });
  
  tape("mat2.setRotation(out, angle)", function(assert) {
      assert.equals(mat2.equals(
          mat2.setRotation([], Math.PI / 2), [0, 1, -1, 0]
      ), true);
      assert.end();
  });
  
  tape("mat2.rotate(out, a, angle)", function(assert) {
      assert.equals(mat2.equals(
          mat2.rotate([], [1, 0, 0, 1], Math.PI / 2), [0, 1, -1, 0]
      ), true);
      assert.end();
  });
  