/// <summary>
/// Constructs a new span with a specific start and end location.
/// </summary>
/// <param name="start">The beginning of the span.</param>
/// <param name="end">The end of the span.</param>
public SourceSpan(SourceLocation start, SourceLocation end)
{
ValidateLocations(start, end);
this._start = start;
this._end = end;
}