code: func cloneForSpec(specPtr *ForSpec) {
  	clone(&specPtr.Expr)
  	oldOuter := specPtr.Outer
  	if oldOuter != nil {
  		specPtr.Outer = new(ForSpec)
  		*specPtr.Outer = *oldOuter
  		cloneForSpec(specPtr.Outer)
  	}
  	for i := range specPtr.Conditions {
  		clone(&specPtr.Conditions[i].Expr)
  	}
  }
docs: // Updates fields of specPtr to point to deep clones.