async findPosts (filter: FindPostsQuery): Promise<RawPostData[]> {
    const findStructs = this.substrate.findPosts.bind(this.substrate, filter)
    const findContents = this.ipfs.getContentArray.bind(this.ipfs)
    const posts = await this.findDataArray<AnyPostId, Post, IpfsPostContent>(
      filter.ids, findStructs, findContents