Verbose messages are printed during optimization

[hongyuanjia]

* Check whether terminator conditions are met
── Generation [17] ────────────────────────────────────────────────────
 * Generate offspring
 * Evaluate fitness values
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
Target object does not refer to any objects.
 * Evaluate fitness values --> Average fitness: 700364.673805543
 * Prepare next generation
 * Update log
 * Check whether terminator conditions are met
── Generation [18] ────────────────────────────────────────────────────