Complete the function that counts the number of unique consonants in a string (made up of printable ascii characters).
Consonants are letters used in English other than `"a", "e", "i", "o", "u"`. We will count `"y"` as a consonant.
Remember, your function needs to return the number of unique consonants - disregarding duplicates. For example, if the string passed into the function reads `"add"`, the function should return `1` rather than `2`, since `"d"` is a duplicate.
Similarly, the function should also disregard duplicate consonants of differing cases. For example, `"Dad"` passed into the function should return `1` as `"d"` and `"D"` are duplicates.
## Examples
```
"add" ==> 1
"Dad" ==> 1
"aeiou" ==> 0
"sillystring" ==> 7
"abcdefghijklmnopqrstuvwxyz" ==> 21
"Count my unique consonants!!" ==> 7
```
CONSONANTS = set('bcdfghjklmnpqrstvwxyz')

def count_consonants(text):
    return len(CONSONANTS.intersection(text.lower()))
CONSONANTS = set('bcdfghjklmnpqrstvwxyz')

def count_consonants(text):
    return len(CONSONANTS.intersection(text.lower()))