Given labels for sex or gender, try to infer which (if any) refer to males. If no elements look like a label for males, or if two or more elements do, then return NULL.
find_label_male(nms)
Arguments
nms: A character vector
Returns
An element of nms or NULL.
Examples
find_label_male(c("Female","Male"))## one validfind_label_male(c("0-4","5-9"))## none validfind_label_male(c("male","m"))## two valid