docstr: Just collects all buckets keys from subtree
docstr_tok: ["Just","collects","all","buckets","keys","from","subtree"]
code: def collect_all_bucket_keys(self):
      """
      Just collects all buckets keys from subtree
      """
      if len(self.childs) == 0:
          # This is a leaf so just return the bucket key (we reached the bucket leaf)
          # print 'Returning (collect) leaf bucket key %s with %d vectors' % (self.bucket_key, self.vector_count)
          return [self.bucket_key]
  
      # Not leaf, return results of childs
      result = []
      for child in self.childs.values():
          result = result + child.collect_all_bucket_keys()
  
      return result
  
file_path: NearPy/nearpy/hashes/randombinaryprojectiontree.py
imports: import numpy
  import scipy
  import scipy.sparse
  from nearpy.hashes.lshash import LSHash
label_desc: Use image node_id 3 for calling the RandomBinaryProjectionTreeNode obj's underlying member method code with example usage: obj.collect_all_bucket_keys() and returns: result, list