The function removes any spaces from the input string, and repeats each character twice.

[CODE]:
```
def f(x):
    x = x.replace(" ", "")
    result = ""
    for char in x:
        result += char * 2
    return result
```

This code snippet approximates the behavior of the function by removing spaces from the string `x` using the `replace()` method, and then iterating over each character and appending it twice to the `result` string.