How to use the pymc3.util.get_variable_name function in pymc3

def _repr_latex_(self, name=None, dist=None):
        if dist is None:
            dist = self
        nu = dist.nu
        mu = dist.mu
        lam = dist.lam
        name = r'\text{%s}' % name
        return r'${} \sim \text{{StudentT}}(\mathit{{nu}}={},~\mathit{{mu}}={},~\mathit{{lam}}={})$'.format(name,
                                                                get_variable_name(nu),
                                                                get_variable_name(mu),
                                                                get_variable_name(lam))

def _repr_latex_(self, name=None, dist=None):
        if dist is None:
            dist = self
        k = dist.k
        tau_e = dist.tau_e
        name = r"\text{%s}" % name
        return r"${} \sim \text{{AR1}}(\mathit{{k}}={},~\mathit{{tau_e}}={})$".format(
            name, get_variable_name(k), get_variable_name(tau_e)
        )

def _repr_latex_(self, name=None, dist=None):
        if dist is None:
            dist = self
        p = dist.p
        name = r'\text{%s}' % name
        return r'${} \sim \text{{Bernoulli}}(\mathit{{p}}={})$'.format(name,
                                                get_variable_name(p))

def _repr_latex_(self, name=None, dist=None):
        if dist is None:
            dist = self
        sigma = dist.sigma
        mu = dist.mu
        name = r'\text{%s}' % name
        return r'${} \sim \text{{Normal}}(\mathit{{mu}}={},~\mathit{{sigma}}={})$'.format(name,
                                                                get_variable_name(mu),
                                                                get_variable_name(sigma))

def _repr_latex_(self, name=None, dist=None):
        if dist is None:
            dist = self
        n = dist.n
        p = dist.p
        name = r'\text{%s}' % name
        return r'${} \sim \text{{Binomial}}(\mathit{{n}}={},~\mathit{{p}}={})$'.format(name,
                                                get_variable_name(n),
                                                get_variable_name(p))

def _repr_latex_(self, name=None, dist=None):
        if dist is None:
            dist = self
        theta = dist.theta
        psi = dist.psi
        name = r'\text{%s}' % name
        return r'${} \sim \text{{ZeroInflatedPoisson}}(\mathit{{theta}}={},~\mathit{{psi}}={})$'.format(name,
                                                get_variable_name(theta),
                                                get_variable_name(psi))

def _repr_latex_(self, name=None, dist=None):
        if dist is None:
            dist = self
        alpha = dist.alpha
        beta = dist.beta
        name = r'\text{%s}' % name
        return r'${} \sim \text{{Cauchy}}(\mathit{{alpha}}={},~\mathit{{beta}}={})$'.format(name,
                                                                get_variable_name(alpha),
                                                                get_variable_name(beta))

def _repr_cov_params(self, dist=None):
        if dist is None:
            dist = self
        if self._cov_type == 'chol':
            chol = get_variable_name(self.chol_cov)
            return r'\mathit{{chol}}={}'.format(chol)
        elif self._cov_type == 'cov':
            cov = get_variable_name(self.cov)
            return r'\mathit{{cov}}={}'.format(cov)
        elif self._cov_type == 'tau':
            tau = get_variable_name(self.tau)
            return r'\mathit{{tau}}={}'.format(tau)

def _repr_cov_params(self, dist=None):
        if dist is None:
            dist = self
        if self._cov_type == 'chol':
            chol = get_variable_name(self.chol_cov)
            return r'\mathit{{chol}}={}'.format(chol)
        elif self._cov_type == 'cov':
            cov = get_variable_name(self.cov)
            return r'\mathit{{cov}}={}'.format(cov)
        elif self._cov_type == 'tau':
            tau = get_variable_name(self.tau)
            return r'\mathit{{tau}}={}'.format(tau)

def _repr_latex_(self, name=None, dist=None):
        if dist is None:
            dist = self
        mu = dist.mu
        sd = dist.sd
        name = r"\text{%s}" % name
        return r"${} \sim \text{{GaussianRandomWalk}}(\mathit{{mu}}={},~\mathit{{sd}}={})$".format(
            name, get_variable_name(mu), get_variable_name(sd)
        )