--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/goodjava/logger/ListLayout.java	Sun Feb 23 18:14:32 2020 -0700
@@ -0,0 +1,40 @@
+package goodjava.logger;
+
+
+public final class ListLayout implements Layout {
+	private final Layout[] layouts;
+
+	public ListLayout(final Object... args) {
+		layouts = new Layout[args.length];
+		for( int i=0; i<args.length; i++ ) {
+			Object obj = args[i];
+			if( obj instanceof Layout ) {
+				layouts[i] = (Layout)obj;
+			} else if( obj instanceof String ) {
+				layouts[i] = new StringLayout((String)obj);
+			} else {
+				throw new IllegalArgumentException("arg "+i);
+			}
+		}
+	}
+
+	public String format(LoggingEvent event) {
+		StringBuilder sb = new StringBuilder();
+		for( Layout layout : layouts ) {
+			sb.append( layout.format(event) );
+		}
+		return sb.toString();
+	}
+
+	private static final class StringLayout implements Layout {
+		final String s;
+
+		StringLayout(String s) {
+			this.s = s;
+		}
+
+		public String format(LoggingEvent event) {
+			return s;
+		}
+	}
+}