Find which strings are valid GWAS Catalog study accession IDs (returns
TRUE). Study accession IDs are tested against the following regular
expression: ^GCST\\d+$.
is_study_id(str, convert_NA_to_FALSE = TRUE)A logical vector.
A character vector of strings.
Whether to treat NA as NA
(convert_NA_to_FALSE = FALSE) or whether to return FALSE when
an NA is found (convert_NA_to_FALSE = TRUE).