How to use the idutils.normalize_pid function in idutils

def normalize_identifier(self, data):
        """Normalize identifier."""
        data['identifier'] = idutils.normalize_pid(
            data['identifier'], data['scheme'])

def _deserialize(self, value, attr, data):
        """Deserialize persistent identifier value."""
        value = super(PersistentId, self)._deserialize(value, attr, data)
        value = value.strip()

        schemes = idutils.detect_identifier_schemes(value)
        if self.scheme and self.scheme.lower() not in schemes:
            self.fail('invalid_scheme', scheme=self.scheme)
        if not schemes:
            self.fail('invalid_pid')
        return idutils.normalize_pid(value, schemes[0]) \
            if self.normalize else value