template function
It takes a string and replaces all the 'a' characters with a random lowercase letter, all the 'A' characters with a random uppercase letter, and all the '#' characters with a random number
Args: temp (String): The template string.
Returns: A string
Implementation
String template(String temp) {
String char = temp;
char = char.replaceAll(
'a',
character(casing: Casing.lower),
);
char = char.replaceAll(
'A',
character(casing: Casing.upper),
);
char = char.replaceAll(
'#',
character(
numeric: true,
),
);
return char;
}