How to use the fitter.utils.print.eprint function in fitter

def _load_storage_config(self, storage_config):
        if 'store' not in storage_config:
            eprint('You must set the \'store\' of \'storage\'')
            sys.exit(0)
        if 'source' in storage_config:
            if not self._validate_storage_fields(storage_config['source']):
                sys.exit(0)
            if not self._validate_storage_fields(storage_config['store']):
                sys.exit(0)
            source_config = storage_config['source']
            store_config = storage_config['store']
        else:
            if not self._validate_storage_fields(storage_config['store']):
                sys.exit(0)
            source_config = storage_config['store']
            store_config = storage_config['store']
        self.SOURCE_STORAGE = self._choose_storage_type(source_config)
        self.STORE_STORAGE = self._choose_storage_type(store_config)

def __init__(self):
        config = self._load_config_file()
        self.PORT = config.get('port', 6001)
        self.SECRET_KEY = config.get('secret_key', None)
        # Cache store is optional field
        if 'cache_store' in config:
            self._load_cache_store_config(config['cache_store'])
        # Options is optional field
        if 'options' in config:
            self._load_options_config(config['options'])
        # Storage is required field
        if 'storage' in config:
            self._load_storage_config(config['storage'])
        else:
            eprint('You must set the \'storage\' config')
            sys.exit(-1)

def __init__(self, aws_access_key_id, aws_secret_access_key, bucket_name, bucket_region, location, **kwargs):
        if not S3Storage.is_valid_region(bucket_region):
            eprint('\'{}\' region is not valid for S3'.format(bucket_region))
            sys.exit(-1)
        self.TYPE = 's3'
        self.AWS_ACCESS_KEY_ID = aws_access_key_id
        self.AWS_SECRET_ACCESS_KEY = aws_secret_access_key
        self.BUCKET_NAME = bucket_name
        self.BUCKET_REGION = bucket_region
        self.LOCATION = location

def _validate_cache_store_fields(cache_store_config):
        _required_fields = ('type',)
        if not all(map(lambda e: e in cache_store_config, _required_fields)):
            eprint('There are some missing values for cache store: one of {}'.format(_required_fields))
            return False
        if cache_store_config['type'] not in ('redis', 'in-memory'):
            eprint('\'{}\' is not supported type for cache store'.format(cache_store_config['type']))
            return False
        return True

_required_fields_for_fs_storage = ('location',)
        _required_fields_for_s3_storage = (
            'aws_access_key_id', 'aws_secret_access_key', 'bucket_name', 'bucket_region', 'location')
        if not all(map(lambda e: e in storage_config, _required_fields)):
            eprint('There are some missing values for storage: one of {}'.format(_required_fields))
            return False
        if storage_config['type'] == 'fs':
            if not all(map(lambda e: e in storage_config, _required_fields_for_fs_storage)):
                eprint('There are some missing values of \'file system\' backed storage')
                return False
        elif storage_config['type'] == 's3':
            if not all(map(lambda e: e in storage_config, _required_fields_for_s3_storage)):
                eprint('There are some missing values of \'s3\' backed storage')
                return False
        else:
            eprint('{} is not supported storage type'.format(storage_config['type']))
            return False
        return True

def _validate_storage_fields(storage_config):
        _required_fields = ('type',)
        _required_fields_for_fs_storage = ('location',)
        _required_fields_for_s3_storage = (
            'aws_access_key_id', 'aws_secret_access_key', 'bucket_name', 'bucket_region', 'location')
        if not all(map(lambda e: e in storage_config, _required_fields)):
            eprint('There are some missing values for storage: one of {}'.format(_required_fields))
            return False
        if storage_config['type'] == 'fs':
            if not all(map(lambda e: e in storage_config, _required_fields_for_fs_storage)):
                eprint('There are some missing values of \'file system\' backed storage')
                return False
        elif storage_config['type'] == 's3':
            if not all(map(lambda e: e in storage_config, _required_fields_for_s3_storage)):
                eprint('There are some missing values of \'s3\' backed storage')
                return False
        else:
            eprint('{} is not supported storage type'.format(storage_config['type']))
            return False
        return True

def _validate_cache_store_fields(cache_store_config):
        _required_fields = ('type',)
        if not all(map(lambda e: e in cache_store_config, _required_fields)):
            eprint('There are some missing values for cache store: one of {}'.format(_required_fields))
            return False
        if cache_store_config['type'] not in ('redis', 'in-memory'):
            eprint('\'{}\' is not supported type for cache store'.format(cache_store_config['type']))
            return False
        return True

def _validate_storage_fields(storage_config):
        _required_fields = ('type',)
        _required_fields_for_fs_storage = ('location',)
        _required_fields_for_s3_storage = (
            'aws_access_key_id', 'aws_secret_access_key', 'bucket_name', 'bucket_region', 'location')
        if not all(map(lambda e: e in storage_config, _required_fields)):
            eprint('There are some missing values for storage: one of {}'.format(_required_fields))
            return False
        if storage_config['type'] == 'fs':
            if not all(map(lambda e: e in storage_config, _required_fields_for_fs_storage)):
                eprint('There are some missing values of \'file system\' backed storage')
                return False
        elif storage_config['type'] == 's3':
            if not all(map(lambda e: e in storage_config, _required_fields_for_s3_storage)):
                eprint('There are some missing values of \'s3\' backed storage')
                return False
        else:
            eprint('{} is not supported storage type'.format(storage_config['type']))
            return False
        return True