code: func validateCSINodeDriverNodeID(nodeID string, fldPath *field.Path) field.ErrorList {
  	allErrs := field.ErrorList{}
  
  	// nodeID is always required
  	if len(nodeID) == 0 {
  		allErrs = append(allErrs, field.Required(fldPath, nodeID))
  	}
  	if len(nodeID) > csiNodeIDMaxLength {
  		allErrs = append(allErrs, field.Invalid(fldPath, nodeID, fmt.Sprintf("must be %d characters or less", csiNodeIDMaxLength)))
  	}
  	return allErrs
  }
docs: // validateCSINodeDriverNodeID tests if Name in CSINodeDriver is a valid node id.