joaocsousa

import java.util.concurrent.TimeUnit;
import io.reactivex.Observable;
import io.reactivex.ObservableSource;
import io.reactivex.ObservableTransformer;
import io.reactivex.Observer;
import io.reactivex.functions.Consumer;

public static class CacheObservable<T> implements ObservableTransformer<T, T> {

    private final long timeout;

brenopolanski

A simple Ghostscript command to merge two PDFs in a single file is shown below:

gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=combine.pdf -dBATCH 1.pdf 2.pdf

Install Ghostscript:

Type the command sudo apt-get install ghostscript to download and install the ghostscript package and all of the packages it depends on.