src/main/java/com/conveyal/gtfs/error/NewGTFSError.java
public static NewGTFSError forLine (Table table, int lineNumber, NewGTFSErrorType errorType, String badValue) {
        NewGTFSError error = new NewGTFSError(table.getEntityClass(), errorType);
        error.lineNumber = lineNumber;
        error.badValue = badValue;
        return error;
    }
public static NewGTFSError forLine (Table table, int lineNumber, NewGTFSErrorType errorType, String badValue) {
        NewGTFSError error = new NewGTFSError(table.getEntityClass(), errorType);
        error.lineNumber = lineNumber;
        error.badValue = badValue;
        return error;
    }
Factory Builder for cases where an entity has not yet been constructed, but we know the line number.