'Set the attribute of the symbol.
Parameters
**kwargs
The attributes to set'

def _set_attr(self, **kwargs):

    keys = c_array(ctypes.c_char_p, [c_str(key) for key in kwargs])
    vals = c_array(ctypes.c_char_p, [c_str(str(val)) for val in kwargs.values()])
    num_args = mx_uint(len(kwargs))
    check_call(_LIB.MXSymbolSetAttrs(self.handle, num_args, keys, vals))
