The 'ldap' provider misses 'ldap' extra dep (which adds ldap3 pip dependency).
setup.py
'google-cloud-monitoring>=0.34.0,<2.0.0',
    'google-cloud-os-login>=2.0.0,<3.0.0',
    'google-cloud-pubsub>=2.0.0,<3.0.0',
    'google-cloud-redis>=2.0.0,<3.0.0',
    'google-cloud-secret-manager>=0.2.0,<2.0.0',
    'google-cloud-spanner>=1.10.0,<2.0.0',
    'google-cloud-speech>=0.36.3,<2.0.0',
    'google-cloud-storage>=1.30,<2.0.0',
    'google-cloud-tasks>=1.2.1,<2.0.0',
    'google-cloud-texttospeech>=0.4.0,<2.0.0',
    'google-cloud-translate>=1.5.0,<2.0.0',
    'google-cloud-videointelligence>=1.7.0,<2.0.0',
    'google-cloud-vision>=0.35.2,<2.0.0',
    'grpcio-gcp>=0.2.2',
    'json-merge-patch~=0.2',
    'pandas-gbq',
]
grpc = [
    'google-auth>=1.0.0, <2.0.0dev',
    'google-auth-httplib2>=0.0.1',
    'grpcio>=1.15.0',
]
hashicorp = [
    'hvac~=0.10',
]
hdfs = [
    'snakebite-py3',
]
hive = [
    'hmsclient>=0.1.0',