parameters: (self, expr,  fpos=0)
docstring: Test a template-expression to detect errors.
docstring_summary: Test a template-expression to detect errors.
docstring_tokens: Test a template - expression to detect errors .
function: def _testexpr(self, expr,  fpos=0):
          """Test a template-expression to detect errors."""
          try:
              self._testexprfunc(expr)
          except SyntaxError as err:
              raise TemplateSyntaxError(err, self._errpos(fpos))
function_tokens: def _testexpr ( self , expr , fpos = 0 ) : try : self . _testexprfunc ( expr ) except SyntaxError as err : raise TemplateSyntaxError ( err , self . _errpos ( fpos ) )