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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_schema_model():
 """ Returns the schema model that is active in this project. """

    try:
        return django_apps.get_model(settings.POSTGRES_SCHEMA_MODEL, require_ready=False)
    except ValueError:
        raise ImproperlyConfigured("POSTGRES_SCHEMA_MODEL must be of the form 'app_label.model_name'")
    except LookupError:
        raise ImproperlyConfigured(
            "POSTGRES_SCHEMA_MODEL refers to model '%s' that has not been installed" % settings.POSTGRES_SCHEMA_MODEL
        )