public static TextRegion create(TextPosition start, TextPosition end) {
    if (start == TextPosition.NOT_AVAILABLE || end == TextPosition.NOT_AVAILABLE)
      return TextRegion.NOT_AVAILABLE;
    return new TextRegion(start, end);
  }
A region of text spanning all characters between a start position (inclusive)
and an end position (exclusive). Positions are given as line/column pairs
(starting at 1). TextRegion instances are immutable.

@author Peter Niederwieser
spock-core/src/main/java/org/spockframework/runtime/model/TextRegion.java