code: def satisfiesShapeExprRef(cntxt: Context, n: Node, se: ShExJ.shapeExprLabel, c: DebugContext) -> bool:
      
      if c.debug:
          print(f"id: {se}")
      for shape in cntxt.schema.shapes:
          if shape.id == se:
              return satisfies(cntxt, n, shape)
      cntxt.fail_reason = f"{se}: Shape is not in Schema"
      return False
docs: Se is a shapeExprRef and there exists in the schema a shape expression se2 with that id
       and satisfies(n, se2, G, m).