assertEquals(ImmutableMap.of("foo", 'a', "bar", 'b'), table.column(1));
  }

  // This test assumes that the implementation does not support null keys.
  public void testColumnNull() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertThrows(NullPointerException.class, () -> table.column(null));
  }

  public void testColumnSetPartialOverlap() {

     */
    int getLineNumber();

    /**
     * Gets the one-based index of the column containing the problem. The column number should refer to some text file
     * that is given by {@link #getSource()}.
     *
     * @return The one-based index of the column containing the problem or non-positive value if unknown.
     */
    int getColumnNumber();

    /**

     * @param lineNumber The one-based index of the line containing the problem or {@code -1} if unknown.
     * @param columnNumber The one-based index of the column containing the problem or {@code -1} if unknown.
     * @param exception The exception that caused this problem, may be {@code null}.
     */
    public DefaultSettingsProblem(

     * @param source The source of the problem, may be {@code null}.
     * @param lineNumber The one-based index of the line containing the error or {@code -1} if unknown.
     * @param columnNumber The one-based index of the column containing the error or {@code -1} if unknown.
     * @param exception The exception that caused this problem, may be {@code null}.
     */
    // mkleint: does this need to be public?
    public DefaultModelProblem(

        assertTrue(
                message.contains("[ERROR] Missing required dependency @ pom.xml, line 25, column 10"),
                "Message should contain error details with location");

        assertTrue(
                message.contains("[ERROR] Invalid version format @ pom.xml, line 30, column 5"),
                "Message should contain second error details");

        assertTrue(

   * generated by applying the specified functions. If multiple inputs are mapped to the same row
   * and column pair, they will be combined with the specified merging function in encounter order.
   *
   * <p>The returned {@code Collector} will throw a {@code NullPointerException} at collection time
   * if the row, column, value, or merging functions return null on any input.
   *
   * @since 21.0
   */

    //                                                                    ================
    // -----------------------------------------------------
    //                                       Column Property
    //                                       ---------------
    protected final Map<String, PropertyGateway> _epgMap = newHashMap();
    {
        setupEpg(_epgMap, et -> ((ElevateWordToLabel) et).getElevateWordId(),

    public Set<Cell<R, C, V>> cellSet() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.cellSet();
    }

    @Override
    public Map<R, V> column(C columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.column(columnKey);
    }

    @Override
    public Set<C> columnKeySet() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.columnKeySet();
    }

    assertEquals(ImmutableSet.of(immutableCell('a', 1, "blah")), testTable.cellSet());
  }

  public void testColumn() {
    assertEquals(ImmutableMap.of(), testTable.column(0));
    assertEquals(ImmutableMap.of('a', "blah"), testTable.column(1));
  }

  public void testColumnKeySet() {
    assertEquals(ImmutableSet.of(1), testTable.columnKeySet());
  }

  public void testColumnMap() {

        problem = new DefaultProblem(null, null, null, -1, 127, null);
        assertEquals("column 127", problem.getLocation());

        problem = new DefaultProblem(null, null, "SOURCE", 42, 127, null);
        assertEquals("SOURCE, line 42, column 127", problem.getLocation());
    }

    @Test
    void testGetMessage() {