It's time for a Code Golf round!

Isogram 

A word or phrase that has no repeating letters, consecutive or non-consecutive.

Implement a method that checks if the received string is an isogram or not.
Assume the empty string is an isogram. 
Ignore the letter case.

Allowed inputs: A-Z, a-z.

As usual, the shortest solution wins!

Input

"pseudomythical"

Output

1

Note

• Use this code to check the solution length

Rules

1. The signature of the contest entry MUST be:

Class codeGolf.Isogram
{ 

ClassMethod Check(word As %String) As %Boolean
{
  // 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 tests.codeGolf.unittests.TestIsogram Extends %UnitTest.TestCase
   {
   
   Method TestCheckIsIsogram()
   {
       Do $$$AssertTrue(##class(codeGolf.Isogram).Check("uncopyrightable"))
       Do $$$AssertTrue(##class(codeGolf.Isogram).Check("upholstering"))
       Do $$$AssertTrue(##class(codeGolf.Isogram).Check("shlockumentary"))
       Do $$$AssertTrue(##class(codeGolf.Isogram).Check("Isogram"))
       Do $$$AssertTrue(##class(codeGolf.Isogram).Check("rock"))
       Do $$$AssertTrue(##class(codeGolf.Isogram).Check("ambiDEXtrously"))
       Do $$$AssertTrue(##class(codeGolf.Isogram).Check("neurolymphatic"))
       Do $$$AssertTrue(##class(codeGolf.Isogram).Check(""), "an empty string is a valid isogram")
       Do $$$AssertNotTrue(##class(codeGolf.Isogram).Check("goose"))
       Do $$$AssertNotTrue(##class(codeGolf.Isogram).Check("goOse"))
       Do $$$AssertNotTrue(##class(codeGolf.Isogram).Check("Balboa"))
       Do $$$AssertNotTrue(##class(codeGolf.Isogram).Check("isIsogram"))
       Do $$$AssertNotTrue(##class(codeGolf.Isogram).Check("aba"))
       Do $$$AssertNotTrue(##class(codeGolf.Isogram).Check("Silmarillion"))
       Do $$$AssertNotTrue(##class(codeGolf.Isogram).Check("JohnRambo"))
   }
   
   }