bool containsKey(
Object key
)

Returns true if this map contains the given key.

Returns true if any of the keys in the map ar equal to key according to the equality used by the map.

Source

/**
 * Returns true if this map contains the given [key].
 *
 * Returns true if any of the keys in the map ar equal to `key`
 * according to the equality used by the map.
 */
bool containsKey(Object key);