import java.util.function.UnaryOperator;

public class VagrantProgressLogger implements UnaryOperator<String> {

    private static final String HEADING_PREFIX = "==> ";

    private final String squashedPrefix;
    private String lastLine = "";
    private String heading = "";
    private boolean inProgressReport = false;

    public VagrantProgressLogger(String squashedPrefix) {
        this.squashedPrefix = squashedPrefix;

            }

            UnaryOperator<String> progressHandler = vagrantSpec.progressHandler;
            if (progressHandler == null) {
                progressHandler = new VagrantProgressLogger("==> " + extension.getBox() + ": ");
            }
            OutputStream output = execSpec.getStandardOutput();