def METHOD_NAME(
    self, values: Optional[List[str]], request_id: Optional[str]
) -> Optional[List[Optional[str]]]:
    """Returns the hashed version of the provided values. Returns None if the provided value
    is None"""
    if values is None:
        return None
    masking_meta: Dict[
        SecretType, MaskingSecretMeta
    ] = self._build_masking_secret_meta()
    salt: str | None = SecretsUtil.get_or_generate_secret(
        request_id,
        SecretType.salt,
        masking_meta[SecretType.salt],
    )
    masked_values: List[Optional[str]] = []
    for value in values:
        if value is None:
            masked_values.append(None)
            continue
        masked: str = self.algorithm_function(str(value), salt)  # type: ignore
        if self.format_preservation is not None:
            formatter = FormatPreservation(self.format_preservation)
            masked = formatter.format(masked)
        masked_values.append(masked)
    return masked_values