class_docstr: Check that the annotations on each function in the graph match
  what is expected.
class_docstr_tok: ["Check","that","the","annotations","on","each","function","in","the","graph","match","what","is","expected","."]
code: def __call__(self, fn):
      assert (
          fn.attrs["io_used_memory"] == self.expected_io_annotation
      ), "Expected IO annotation did not match."
      self.visit(fn.body)
  
imports: import pytest
  import tvm
  from tvm import relay
  from tvm.relay.expr_functor import ExprVisitor
label_desc: Use image node_id 3 for calling the CheckUsedMemoryAnnotation obj's underlying member method code with example usage: obj.__call__(fn) without return types