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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def access(cls, parent, placeholder):
 """Resolve the deferred field attribute access. :param cls: the FieldAccessor class :param parent: owning structure of the field being accessed :param placeholder: FieldPlaceholder object which holds our info :returns: FieldAccessor instance for that field's attribute """

        try:
            return parent.lookup_field_by_placeholder(placeholder)
        except KeyError:
            field_placeholder, name = placeholder.args
            # Find the field whose attribute is being accessed.
            field = parent.lookup_field_by_placeholder(field_placeholder)
            # Instantiate the real FieldAccessor that wraps the attribute.
            accessor = cls(field, name, parent=parent, instantiate=True)
            # Keep this instance alive, and reuse it for future references.
            parent._placeholder_to_field[placeholder] = accessor
            return accessor