How to use the pyuvdata._miriad.hread function in pyuvdata

if itype == "?":
            return self._rdhd_special(name)

        h = self.haccess(name, "read")
        rv = []

        if len(itype) == 1:
            if itype == "a":
                offset = 0
            else:
                t, offset = _miriad.hread_init(h)
                assert itype == t

            while True:
                try:
                    c, o = _miriad.hread(h, offset, itype)
                except IOError:
                    break

                if itype == "a":
                    try:
                        c = str(c[:o], "utf-8")
                    except TypeError:
                        c = c[:o]

                rv.append(c)
                offset += o

            if itype == "a":
                rv = "".join(rv)
        else:
            t, offset = _miriad.hread_init(h)

try:
                        c = str(c[:o], "utf-8")
                    except TypeError:
                        c = c[:o]

                rv.append(c)
                offset += o

            if itype == "a":
                rv = "".join(rv)
        else:
            t, offset = _miriad.hread_init(h)
            assert t == "b"

            for t in itype:
                v, o = _miriad.hread(h, offset, t)
                rv.append(v)
                offset += o

        _miriad.hdaccess(h)

        if len(rv) == 1:
            return rv[0]
        elif type(rv) == str:
            return rv
        else:
            return np.array(rv)

def _rdhd_special(self, name):
        """Provide read access to special header items of type '?' to _rdhd."""
        if name == "freqs":
            h = self.haccess(name, "read")
            c, o = _miriad.hread(h, 0, "i")
            rv = [c]
            offset = 8

            while True:
                try:
                    c, o = _miriad.hread(h, offset, "i")
                    rv.append(c)
                    offset += 8

                    c, o = _miriad.hread(h, offset, "d")
                    rv.append(c)
                    offset += 8

                    c, o = _miriad.hread(h, offset, "d")
                    rv.append(c)
                    offset += 8
                except IOError:
                    break

            _miriad.hdaccess(h)
            return rv
        else:
            raise ValueError("Unknown special header: " + name)

def _rdhd_special(self, name):
        """Provide read access to special header items of type '?' to _rdhd."""
        if name == "freqs":
            h = self.haccess(name, "read")
            c, o = _miriad.hread(h, 0, "i")
            rv = [c]
            offset = 8

            while True:
                try:
                    c, o = _miriad.hread(h, offset, "i")
                    rv.append(c)
                    offset += 8

                    c, o = _miriad.hread(h, offset, "d")
                    rv.append(c)
                    offset += 8

                    c, o = _miriad.hread(h, offset, "d")
                    rv.append(c)
                    offset += 8

h = self.haccess(name, "read")
            c, o = _miriad.hread(h, 0, "i")
            rv = [c]
            offset = 8

            while True:
                try:
                    c, o = _miriad.hread(h, offset, "i")
                    rv.append(c)
                    offset += 8

                    c, o = _miriad.hread(h, offset, "d")
                    rv.append(c)
                    offset += 8

                    c, o = _miriad.hread(h, offset, "d")
                    rv.append(c)
                    offset += 8
                except IOError:
                    break

            _miriad.hdaccess(h)
            return rv
        else:
            raise ValueError("Unknown special header: " + name)

def _rdhd_special(self, name):
        """Provide read access to special header items of type '?' to _rdhd."""
        if name == "freqs":
            h = self.haccess(name, "read")
            c, o = _miriad.hread(h, 0, "i")
            rv = [c]
            offset = 8

            while True:
                try:
                    c, o = _miriad.hread(h, offset, "i")
                    rv.append(c)
                    offset += 8

                    c, o = _miriad.hread(h, offset, "d")
                    rv.append(c)
                    offset += 8

                    c, o = _miriad.hread(h, offset, "d")
                    rv.append(c)
                    offset += 8
                except IOError:
                    break

            _miriad.hdaccess(h)
            return rv
        else: