for _, test := range testCases {
		a := []byte(test.a)
		actual := f(a, test.b)
		if actual != test.i {
			t.Errorf("%s(%q,%q) = %v; want %v", funcName, a, test.b, actual, test.i)
		}
	}
}

func TestIndex(t *testing.T)     { runIndexTests(t, Index, "Index", indexTests) }
func TestLastIndex(t *testing.T) { runIndexTests(t, LastIndex, "LastIndex", lastIndexTests) }

        dest = growBuffer(dest, destIndex, sizeNeeded);
      }
      s.getChars(lastEscape, slen, dest, destIndex);
      destIndex = sizeNeeded;
    }
    return new String(dest, 0, destIndex);
  }

  /**
   * Helper method to grow the character buffer as needed, this only happens once in a while so it's
   * ok if it's in a method call. If the index passed in is 0 then no copying will be done.
   */

        dest = growBuffer(dest, destIndex, sizeNeeded);
      }
      s.getChars(lastEscape, slen, dest, destIndex);
      destIndex = sizeNeeded;
    }
    return new String(dest, 0, destIndex);
  }

  /**
   * Helper method to grow the character buffer as needed, this only happens once in a while so it's
   * ok if it's in a method call. If the index passed in is 0 then no copying will be done.
   */

    if (charsSkipped > 0) {
      int endIndex = destIndex + charsSkipped;
      if (dest.length < endIndex) {
        dest = growBuffer(dest, destIndex, endIndex);
      }
      s.getChars(unescapedChunkStart, end, dest, destIndex);
      destIndex = endIndex;
    }
    return new String(dest, 0, destIndex);
  }

  /**

    if (charsSkipped > 0) {
      int endIndex = destIndex + charsSkipped;
      if (dest.length < endIndex) {
        dest = growBuffer(dest, destIndex, endIndex);
      }
      s.getChars(unescapedChunkStart, end, dest, destIndex);
      destIndex = endIndex;
    }
    return new String(dest, 0, destIndex);
  }

  /**

        byte[] dest = new byte[5];

        // Expect IndexOutOfBoundsException from System.arraycopy
        assertThrows(IndexOutOfBoundsException.class, () -> {
            encodable.encode(dest, 3); // destIndex=3, len=3, dest.length=5. 3+3 > 5
        }, "Should throw IndexOutOfBoundsException if destination offset + length exceeds destination array bounds");
    }

    @Test
    void testEncodeNullSourceArray() {