/* package whatever; // don't place package name! */
 
import java.util.*;
import java.util.stream.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		final String[] p = { "header1", "header2", "header3"};
		final String[][] b= {{"1", "2", "3"}, {"4", "5", "6"}, {"7", "8", "9"}};
		final Stream<String[]> rows = Arrays.stream(b); //that works
		final Stream<String[]> headers = Stream.<String[]>of(p);
		final Stream<String[]> headersAndRows = Stream.concat(headers, rows); // what we want to accomplish
 
		headersAndRows.forEach(s -> System.out.println(Arrays.toString(s)));
	}
}

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