docs: def visitMultiElementOneOf(self, ctx: ShExDocParser.MultiElementOneOfContext):
          """ multiElementOneOf: groupShape ('|' groupShape)+ """
          self.expression = OneOf(expressions=[])
          for gs in ctx.groupShape():
              parser = ShexOneOfShapeParser(self.context)
              parser.visit(gs)
              self.expression.expressions.append(parser.expression)