fixed a few minor bugs in helpers
fixed a few minor bugs in helpers


Former-commit-id: 01cbc8485a6700698eb5f681aafb2f68390e8857 [formerly 01cbc8485a6700698eb5f681aafb2f68390e8857 [formerly cc3fd0f0733cc4ec379b8af9fa7e1a1cd1f8fa99]]
Former-commit-id: 7c5a37204bc80dc0862b482a02d084080f4a5824
Former-commit-id: ee89794a5c9fc10922b188799edc035f2181f5c8
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine