liquibase-core/src/main/java/liquibase/util/csv/opencsv/CSVReader.java
private boolean isClosed() {
        if (!verifyReader) {
            return false;
        }
        try {
            br.mark(READ_AHEAD_LIMIT);
            int nextByte = br.read();
            br.reset(); // resets stream position, possible because its buffered
            return nextByte == -1; // read() returns -1 at end of stream
        } catch (IOException e) {
            return true;
        }
    }
private boolean isClosed() {
        if (!verifyReader) {
            return false;
        }
        try {
            br.mark(READ_AHEAD_LIMIT);
            int nextByte = br.read();
            br.reset(); // resets stream position, possible because its buffered
            return nextByte == -1; // read() returns -1 at end of stream
        } catch (IOException e) {
            return true;
        }
    }
Checks to see if the file is closed.
@return true if the reader can no longer be read from.