diff --git a/bin/slsb b/bin/slsb
index f7fc6c6..73e661b 100755
--- a/bin/slsb
+++ b/bin/slsb
@@ -29,6 +29,8 @@ try:
 except:
     print "Install stegano: python setup.py install"
 
+from stegano import tools
+
 from optparse import OptionParser
 parser = OptionParser(version=__version__)
 parser.add_option('--hide', action='store_true', default=False,
diff --git a/bin/slsb-set b/bin/slsb-set
index 0fa745e..2afef7c 100755
--- a/bin/slsb-set
+++ b/bin/slsb-set
@@ -29,6 +29,8 @@ try:
 except:
     print "Install stegano: python setup.py install"
 
+from stegano import tools
+
 from optparse import OptionParser
 parser = OptionParser(version=__version__)
 parser.add_option('--hide', action='store_true', default=False,
diff --git a/stegano/generators.py b/stegano/generators.py
index e6f79fc..fbc9860 100644
--- a/stegano/generators.py
+++ b/stegano/generators.py
@@ -26,6 +26,15 @@ __license__ = "GPLv3"
 
 import itertools
 
+def identity():
+    """
+    f(x) = x
+    """
+    n = 0
+    while True:
+        yield n
+        n += 1
+
 def fermat():
     """
     Generate the n-th Fermat Number.