Copies all of the mappings from the specified source map to this map.
Copies all of the mappings from the specified source map to this map. These mappings will replace any mappings that this map had for any of the keys currently in the specified map.For hash maps this method has a time complexity of O(M). For tree maps this method has a time complexity of O(M * Log N). With M being the number of elements in the source map and N being the number of elements in the target map.