nl_tokens: If type has a single call signature and no other members return that signature . Otherwise return undefined .
pl_tokens: function getSingleCallSignature ( type ) { if ( type . flags & 80896 /* ObjectType */ ) { var resolved = resolveStructuredTypeMembers ( <mask> ) ; if ( resolved . callSignatures . length === 1 && resolved . constructSignatures . length === 0 && resolved . properties . length === 0 && ! resolved . stringIndexType && ! resolved . numberIndexType ) { return resolved . callSignatures [ 0 ] ; } } return undefined ; }