diff --git a/selftest/trial_test/invalid_checksum/checksums.md5 b/selftest/trial_test/invalid_checksum/checksums.md5
new file mode 100644
index 0000000..90d3547
--- /dev/null
+++ b/selftest/trial_test/invalid_checksum/checksums.md5
@@ -0,0 +1,3 @@
+5149d403009a139c7e085405ef762e1a  file1
+3d709e89c8ce201e3c928eb917989aef  file2
+60b91f1875424d3b4322b0fdd0529d5d  file3
diff --git a/selftest/trial_test/invalid_checksum/file1 b/selftest/trial_test/invalid_checksum/file1
new file mode 100644
index 0000000..e212970
--- /dev/null
+++ b/selftest/trial_test/invalid_checksum/file1
@@ -0,0 +1 @@
+file1
diff --git a/selftest/trial_test/invalid_checksum/file2 b/selftest/trial_test/invalid_checksum/file2
new file mode 100644
index 0000000..34ccdac
--- /dev/null
+++ b/selftest/trial_test/invalid_checksum/file2
@@ -0,0 +1 @@
+no no no
diff --git a/selftest/trial_test/invalid_checksum/file3 b/selftest/trial_test/invalid_checksum/file3
new file mode 100644
index 0000000..7c8ac2f
--- /dev/null
+++ b/selftest/trial_test/invalid_checksum/file3
@@ -0,0 +1 @@
+file3
diff --git a/selftest/trial_test/missing_file/checksums.md5 b/selftest/trial_test/missing_file/checksums.md5
new file mode 100644
index 0000000..90d3547
--- /dev/null
+++ b/selftest/trial_test/missing_file/checksums.md5
@@ -0,0 +1,3 @@
+5149d403009a139c7e085405ef762e1a  file1
+3d709e89c8ce201e3c928eb917989aef  file2
+60b91f1875424d3b4322b0fdd0529d5d  file3
diff --git a/selftest/trial_test/missing_file/file1 b/selftest/trial_test/missing_file/file1
new file mode 100644
index 0000000..e212970
--- /dev/null
+++ b/selftest/trial_test/missing_file/file1
@@ -0,0 +1 @@
+file1
diff --git a/selftest/trial_test/missing_file/file3 b/selftest/trial_test/missing_file/file3
new file mode 100644
index 0000000..7c8ac2f
--- /dev/null
+++ b/selftest/trial_test/missing_file/file3
@@ -0,0 +1 @@
+file3
diff --git a/selftest/trial_test/valid_checksums/checksums.md5 b/selftest/trial_test/valid_checksums/checksums.md5
new file mode 100644
index 0000000..90d3547
--- /dev/null
+++ b/selftest/trial_test/valid_checksums/checksums.md5
@@ -0,0 +1,3 @@
+5149d403009a139c7e085405ef762e1a  file1
+3d709e89c8ce201e3c928eb917989aef  file2
+60b91f1875424d3b4322b0fdd0529d5d  file3
diff --git a/selftest/trial_test/valid_checksums/file1 b/selftest/trial_test/valid_checksums/file1
new file mode 100644
index 0000000..e212970
--- /dev/null
+++ b/selftest/trial_test/valid_checksums/file1
@@ -0,0 +1 @@
+file1
diff --git a/selftest/trial_test/valid_checksums/file2 b/selftest/trial_test/valid_checksums/file2
new file mode 100644
index 0000000..6c493ff
--- /dev/null
+++ b/selftest/trial_test/valid_checksums/file2
@@ -0,0 +1 @@
+file2
diff --git a/selftest/trial_test/valid_checksums/file3 b/selftest/trial_test/valid_checksums/file3
new file mode 100644
index 0000000..7c8ac2f
--- /dev/null
+++ b/selftest/trial_test/valid_checksums/file3
@@ -0,0 +1 @@
+file3