SchemaColumn(String name, ManagedPropertyType t, { bool isIndexed: false, bool isNullable: false, bool autoincrement: false, bool isUnique: false, String defaultValue, bool isPrimaryKey: false })

Source 

SchemaColumn(this.name, ManagedPropertyType t,
    {this.isIndexed: false,
    this.isNullable: false,
    this.autoincrement: false,
    this.isUnique: false,
    this.defaultValue,
    this.isPrimaryKey: false}) {
  _type = typeStringForType(t);
}