class_docstr: The actual mutator pass to extract the constants from a function and replace them with
  Vars so the function can be lowered to a TE graph. Additionally returns all the values of
  the constants extracted.
code: def visit_constant(self, const):
      if isinstance(const.checked_type, relay.ty.TensorType):
          self.constants.append(const.data.asnumpy())
          name = "p" + str(len(self.constants))
          var = relay.var(
              type_annotation=const.checked_type, name_hint=name
          )
          self.const_vars.append(var)
          return var
  
      return const
  
imports: import tvm
  from tvm import relay
  from tvm.driver.build_module import schedule_to_module
  from tvm.relay.backend.contrib.ethosu import vela_api
  from tvm.relay.expr_functor import ExprMutator
  from ..None import util
  from .None import passes
  from .scheduler import schedule
label_desc: Use image node_id 2 for calling the ExtractConstants obj's underlying member method code with example usage: obj.visit_constant(const) and returns: const, var