check_cnp_is_valid      Check if a CNP is valid
decompose_cnp           Split the CNP into its components
get_birth_month         Extract the Month of Birth from the Personal
                        Numeric Code
get_birth_year          Extract Year of Birth from the Personal Numeric
                        Code
get_county              Extract County of Issue from the Personal
                        Numeric Code
get_sex                 Extract the Sex from the Personal Numeric Code
get_status              Extract Residence Status from the Personal
                        Numeric Code
