in lib/src/context.dart [1084:1104]
void _validateArgList(String method, List<String?> args) {
for (var i = 1; i < args.length; i++) {
// Ignore nulls hanging off the end.
if (args[i] == null || args[i - 1] != null) continue;
int numArgs;
for (numArgs = args.length; numArgs >= 1; numArgs--) {
if (args[numArgs - 1] != null) break;
}
// Show the arguments.
final message = StringBuffer();
message.write('$method(');
message.write(args
.take(numArgs)
.map((arg) => arg == null ? 'null' : '"$arg"')
.join(', '));
message.write('): part ${i - 1} was null, but part $i was not.');
throw ArgumentError(message.toString());
}
}