Code Golf: Multi-Tap technique

Multi-tap or multi-press is the name given to the historic technique of writing SMS on the first mobile phones with a keyboard of 10-12 numeric keys.
For example, to type LOL you need to press 5 three times, 6 three times and 5 three times again.
Your task is to write a function that takes a string as input and returns the repeated digits associated with each character according to the multi-tap system.
Should consider letters from A to Z, doesn't distinguish between upper/lowercase characters.
Numbers are allowed, and any punctuation should be ignored.

Input

"Example"

Output

"339926755533"

Note

• Use this code to check the solution length

Rules

1. The signature of the contest entry MUST be:

   Class codeGolf.MultiTap Extends %RegisteredObject
   {
       ClassMethod ToKeyPad(phrase) As %String
       {
           Return "" // Your solution here
       }
   
   }
   

2. It is forbidden to modify class/signature, including but not limited to:

   • Adding inheritance
   • Setting default argument values
   • Adding class elements (Parameters, Methods, Includes, etc).

3. It is forbidden to refer to non-system code from your entry. For example, this is not a valid entry:

   ClassMethod Build(f As %Integer)
   {
     W ##class(myPackage.myClass).test(a)
   }
   

4. The use of $ZWPACK and $ZWBPACK is also discouraged.

5. You can use this test case:

   Class codeGolf.unittest.MultiTap Extends %UnitTest.TestCase
   {
       Method TestMultiTap()
       {
           Do $$$AssertEquals(##class(codeGolf.MultiTap).ToKeyPad("Example"), "339926755533")
           Do $$$AssertEquals(##class(codeGolf.MultiTap).ToKeyPad("Dumbphone TEXT"), "38862274466666330833998")
           Do $$$AssertEquals(##class(codeGolf.MultiTap).ToKeyPad("InterSystems IRIS"), "44466833777777799977778336777704447774447777")
           Do $$$AssertEquals(##class(codeGolf.MultiTap).ToKeyPad("Code Golf"), "22266633304666555333")
           Do $$$AssertEquals(##class(codeGolf.MultiTap).ToKeyPad("L33T C0d3r"), "55533333333802220033333777")
       }
   }