src/main/java/io/github/oliviercailloux/swt_tools/IntEditingSupport.java
public void setIntegerValidator(Function<Integer, String> valueToErrorMessage) {
		setValidator(valueToErrorMessage.compose(v -> Integer.valueOf(v)));
	}
public void setIntegerValidator(Function<Integer, String> valueToErrorMessage) {
		setValidator(valueToErrorMessage.compose(v -> Integer.valueOf(v)));
	}
<p>
Sets the input validator for this cell editor.
</p>
<p>
The validator is given the (integer) value to be validated, and must return a
string indicating whether the given value is valid; <code>null</code> means
valid, and non-<code>null</code> means invalid, with the result being the
error message to display to the end user.
</p>
<p>
This is simply a better-typed version of {@link #setValidator(Function)}.
</p>

@param valueToErrorMessage
the input validator, or <code>null</code> if none