When identifying errors such as
```
onlineapp.d(4): Error: undefined identifier InterpolationHeader
onlineapp.d(47): Error: template heresy is not callable using argument types !()(InterpolationHeader, InterpolatedLiteral!"http://localhost:8000/users/userid=", InterpolatedExpression!"i", int, InterpolationFooter)
onlineapp.d(4): Candidate is: heresy(Args...)(InterpolationHeader header, Args args, InterpolationFooter footer)
```
InterpolationHeader, InterpolationFooter, the compiler could suggest the import as it can be tricky for someone starting to use the interpolation feature.