static range(e, t) {
    return t ? !e || !e.loc || !t.loc || e.loc.lexer !== t.loc.lexer ? null : new u0(e.loc.lexer, e.loc.start, t.loc.end) : e && e.loc;
  }
Merges two `SourceLocation`s from location providers, given they are
provided in order of appearance.
- Returns the first one's location if only the first is provided.
- Returns a merged range of the first and the last if both are provided
  and their lexers match.
- Otherwise, returns null.