This coding principle emphasizes the importance of using `if-condition` for
`optional` arguments or variables, and ensuring that they have a "not null"
condition.
By doing so, it helps prevent unexpected errors or bugs in the code
that can arise from assuming the presence of `optional` arguments or variables
without checking their values first.
-- component school:
optional string name:
-- ftd.text: $school.name
-- end: school
-- component school:
optional string name:
-- ftd.text: $school.name
if: { school.name != NULL }
-- end: school