parse method
Parse the env lines into map values and return it back
Implementation
Map<String, String> parse(Iterable<String> lines) {
var out = <String, String>{};
lines.forEach((line) {
var kv = parseOne(line, env: out);
if (kv.isEmpty) return;
out.putIfAbsent(kv.keys.single, () => kv.values.single);
});
return out;
}