@Test
public void testNormalizeSpace() {

    assertNull(normalizeVariableName(null));
    assertEquals("", normalizeVariableName(""));
    assertEquals("", normalizeVariableName(" "));
    assertEquals("", normalizeVariableName("\t"));
    assertEquals("", normalizeVariableName("\n"));
    assertEquals("", normalizeVariableName("\u0009"));
    assertEquals("", normalizeVariableName("\u000B"));
    assertEquals("", normalizeVariableName("\u000C"));
    assertEquals("", normalizeVariableName("\u001C"));
    assertEquals("", normalizeVariableName("\u001D"));
    assertEquals("", normalizeVariableName("\u001E"));
    assertEquals("", normalizeVariableName("\u001F"));
    assertEquals("", normalizeVariableName("\f"));
    assertEquals("", normalizeVariableName("\r"));
    assertEquals("a", normalizeVariableName("  a  "));
    assertEquals("a b c", normalizeVariableName("  a  b   c  "));
    assertEquals("a b c", normalizeVariableName("a\t\f\r  b\u000B   c\n"));
    assertEquals("a b c", normalizeVariableName("a\t\f\r  \u00A0\u00A0b\u000B   c\n"));
    assertEquals("b", normalizeVariableName(" b"));
    assertEquals("b", normalizeVariableName("b "));
    assertEquals("ab c", normalizeVariableName("ab c  "));
    assertEquals("a b", normalizeVariableName("a\u00A0b"));
}