Typecheck functions not working

[mihai-stancu]

Hi,

I've noticed that the typecheck functions are always returning false on my install.

I'm running Ubuntu 22.04 with Python 3.10.12 and have installed emrichen 0.4.0 via pip install emrichen at version.

# x.yml
!Defaults

number: 1234
dict:
  key: 4321

---
test_number_isnumber: !IsNumber number
test_dict_isdict: !IsDict dict

test_number_isinteger: !IsInteger number

test_number_isstring: !IsString number
test_dict_isstring: !IsString dict

$ emrichen < x.yml 
> test_number_isnumber: false
> test_dict_isdict: false
> test_number_isinteger: false
> test_number_isstring: true
> test_dict_isstring: true