def visitPrefixDecl(self, ctx: ShExDocParser.PrefixDeclContext):
iri = self.context.iriref_to_shexj_iriref(ctx.IRIREF())<EOL>prefix = ctx.PNAME_NS().getText()<EOL>if iri not in self.context.ld_prefixes:<EOL><INDENT>self.context.prefixes.setdefault(prefix, iri.val)<EOL><DEDENT>
prefixDecl: KW_PREFIX PNAME_NS IRIREF