code: func (c *ClaimTreeClient) List(ctx context.Context, orgID *identity.ID,
  	ownerID *identity.ID) ([]ClaimTree, error) {
  
  	query := &url.Values{}
  	if orgID != nil {
  		query.Set("org_id", orgID.String())
  	}
  
  	if ownerID != nil {
  		query.Set("owner_id", ownerID.String())
  	}
  
  	var resp []ClaimTree
  	err := c.client.RoundTrip(ctx, "GET", "/claimtree", query, nil, &resp)
  	return resp, err
  }
docs: // List returns a list of all claimtrees for a given orgID. If no orgID is
  // provided then it returns all claimtrees for every organization the user
  // belongs too.
  //
  // If an ownerID is provided then only public keys and claims related to that
  // user or machine will be returned.