equals method
Determines if the contents of this map and other
are equal.
Implementation
bool equals(Map<K, V> other) {
if (identical(this, other)) {
return true;
}
if (length != other.length) {
return false;
}
for (final entry in entries) {
if (entry.value != other[entry.key]) {
return false;
}
}
return true;
}