diff --git a/src/main/java/com/sshtools/jini/INI.java b/src/main/java/com/sshtools/jini/INI.java
index 30266fe..f88636e 100644
--- a/src/main/java/com/sshtools/jini/INI.java
+++ b/src/main/java/com/sshtools/jini/INI.java
@@ -1241,50 +1241,4 @@ public Entry<String, V> next() {
         }
 
     }
-	@SuppressWarnings("unchecked")
-	public static Function<String, String> compound(Function<String, String>... sources)  {
-		return (k) -> {
-			for(var src : sources) {
-				var v = src.apply(k);
-				if(v != null)
-					return v;
-			}
-			return null;
-		};
-	}
-	
-	public static Function<String, String> systemProperties()  {
-		return (k) -> {
-			if(k.startsWith("sys.")) {
-				return System.getProperty(k.substring(4));
-			}
-			else if(k.startsWith("env.")) {
-				return System.getenv(k.substring(4));
-			}
-			else
-				return null;
-		};
-	}
-
-	public static String str(String text, Function<String, String> source) {
-		var pattern = Pattern.compile("\\$\\{(.*?)\\}");
-		var matcher = pattern.matcher(text);
-		var builder = new StringBuilder();
-		int i = 0;
-		while (matcher.find()) {
-			var variable = matcher.group(1);
-			var replacement = source.apply(variable);
-			builder.append(text.substring(i, matcher.start()));
-			if (replacement == null) {
-				throw new IllegalArgumentException(MessageFormat.format("Unknown string variable $\\{{0}\\}", variable));
-			} else {
-				builder.append(replacement);
-			}
-			i = matcher.end();
-
-		}
-		builder.append(text.substring(i, text.length()));
-		text = builder.toString();
-		return text;
-	}
 }
diff --git a/src/main/java/com/sshtools/jini/INIPreferences.java b/src/main/java/com/sshtools/jini/INIPreferences.java
index df87fe6..5410199 100644
--- a/src/main/java/com/sshtools/jini/INIPreferences.java
+++ b/src/main/java/com/sshtools/jini/INIPreferences.java
@@ -87,9 +87,6 @@ public INIStoreBuilder withFailOnParsingError(boolean failOnParsingError) {
 		}
 
 		public INIStoreBuilder withMode(Mode mode) {
-			if (customRoot.isPresent() && scope != Scope.CUSTOM) {
-				throw new IllegalArgumentException("A custom root has been set. Scope may not be used.");
-			}
 			this.mode = mode;
 			return this;
 		}
diff --git a/src/main/java/com/sshtools/jini/Interpolation.java b/src/main/java/com/sshtools/jini/Interpolation.java
new file mode 100644
index 0000000..de4c183
--- /dev/null
+++ b/src/main/java/com/sshtools/jini/Interpolation.java
@@ -0,0 +1,55 @@
+package com.sshtools.jini;
+
+import java.text.MessageFormat;
+import java.util.function.Function;
+import java.util.regex.Pattern;
+
+public class Interpolation {
+
+	@SuppressWarnings("unchecked")
+	public static Function<String, String> compound(Function<String, String>... sources)  {
+		return (k) -> {
+			for(var src : sources) {
+				var v = src.apply(k);
+				if(v != null)
+					return v;
+			}
+			return null;
+		};
+	}
+	
+	public static Function<String, String> systemProperties()  {
+		return (k) -> {
+			if(k.startsWith("sys.")) {
+				return System.getProperty(k.substring(4));
+			}
+			else if(k.startsWith("env.")) {
+				return System.getenv(k.substring(4));
+			}
+			else
+				return null;
+		};
+	}
+
+	public static String str(String text, Function<String, String> source) {
+		var pattern = Pattern.compile("\\$\\{(.*?)\\}");
+		var matcher = pattern.matcher(text);
+		var builder = new StringBuilder();
+		int i = 0;
+		while (matcher.find()) {
+			var variable = matcher.group(1);
+			var replacement = source.apply(variable);
+			builder.append(text.substring(i, matcher.start()));
+			if (replacement == null) {
+				throw new IllegalArgumentException(MessageFormat.format("Unknown string variable $\\{{0}\\}", variable));
+			} else {
+				builder.append(replacement);
+			}
+			i = matcher.end();
+
+		}
+		builder.append(text.substring(i, text.length()));
+		text = builder.toString();
+		return text;
+	}
+}
diff --git a/src/test/java/com/sshtools/jini/INITest.java b/src/test/java/com/sshtools/jini/INITest.java
index 6d1ebe0..b7b1de3 100644
--- a/src/test/java/com/sshtools/jini/INITest.java
+++ b/src/test/java/com/sshtools/jini/INITest.java
@@ -21,6 +21,7 @@
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.Reader;
 import java.io.UncheckedIOException;
@@ -113,6 +114,32 @@ public void testReadFromFile() throws Exception {
         assertBasicInsensitive(ini);
     }
 
+    @Test
+    public void testReadFromStream() throws Exception {
+        var ini = INI.fromInput(new ByteArrayInputStream(getBasicIni().getBytes()));
+        assertBasic(ini);
+        assertBasicOrder(ini);
+        assertBasicInsensitive(ini);
+    }
+
+    @Test
+    public void testReadOnly() throws Exception {
+    	assertThrows(UnsupportedOperationException.class, () -> {
+            var ini = INI.fromString(getBasicIni()).readOnly();
+            ini.put("abc", true);
+    	});
+    }
+
+    @Test
+    public void testEmpty() throws Exception {
+    	assertThrows(UnsupportedOperationException.class, () -> {
+            var ini = INI.empty();
+            assertEquals(0, ini.keys().size());
+            assertEquals(0, ini.sections().size());
+            ini.put("abc", true);
+    	});
+    }
+
     @Test
     public void testFailReadFromFile() throws Exception {
         assertThrows(UncheckedIOException.class, () -> INI.fromFile(Paths.get(UUID.randomUUID().toString())));