dcatStartDate constant
startDate from dcat vocabulary [Expects: http://www.w3.org/2000/01/rdf-schema#Literal]
Can be used on: http://purl.org/dc/terms/PeriodOfTime
Implementation
static const dcatStartDate = IriTerm.prevalidated(
'http://www.w3.org/ns/dcat#startDate',
);