ExtraMaterial.fromJson constructor
      
      ExtraMaterial.fromJson(
    
    
- Map json_
 
Implementation
ExtraMaterial.fromJson(core.Map json_)
  : this(
      link:
          json_.containsKey('link')
              ? TextLink.fromJson(
                json_['link'] as core.Map<core.String, core.dynamic>,
              )
              : null,
      video:
          json_.containsKey('video')
              ? VideoLink.fromJson(
                json_['video'] as core.Map<core.String, core.dynamic>,
              )
              : null,
    );