README.md in trackler-2.2.1.105

- old
+ new

@@ -1,6 +1,7 @@
 # Phone Number
+
 Clean up user-entered phone numbers so that they can be sent SMS messages.
 
 The **North American Numbering Plan (NANP)** is a telephone numbering system used by many countries in North America like the United States, Canada or Bermuda. All NANP-countries share the same international country code: `1`.
 
 NANP numbers are ten-digit numbers consisting of a three-digit Numbering Plan Area code, commonly known as *area code*, followed by a seven-digit local number. The first three digits of the local number represent the *exchange code*, followed by the unique four-digit number which is the *subscriber number*.
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 `6139950253`
 
 **Note:** As this exercise only deals with telephone numbers used in NANP-countries, only 1 is considered a valid country code.
 
-# Tip
+## Tip
+
 A function with a *return type* can only return data of that *type* and `null`.
 However the function caller is only expecting one data type.
 
 Example:
 ```dart
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         return "a";
     } else {
         return null;
     }
 }
+
+
+
+To run the tests:
+
+```sh
+$ pub run test
 ```
 
+For more detailed info about the Dart track see the [help page](http://exercism.io/languages/dart).
+
+## Source
+
+Event Manager by JumpstartLab [http://tutorials.jumpstartlab.com/projects/eventmanager.html](http://tutorials.jumpstartlab.com/projects/eventmanager.html)
+
 ## Submitting Incomplete Solutions
-It's possible to submit an incomplete solution so you can see how others have completed the exercise.
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+It's possible to submit an incomplete solution so you can see how others have completed the exercise.