$resource
$resource : resource|null
Implementation of PSR HTTP streams
__toString() : string
Reads all data from the stream into a string, from the beginning to end.
This method MUST attempt to seek to the beginning of the stream before reading data and read the stream until the end is reached.
Warning: This could attempt to load a large amount of data into memory.
This method MUST NOT raise an exception in order to conform with PHP's string casting operations.
seek(integer $offset, integer $whence = \SEEK_SET)
Seek to a position in the stream.
| integer | $offset | Stream offset  | 
                            
| integer | $whence | Specifies how the cursor position will be calculated
based on the seek offset. Valid values are identical to the built-in
PHP $whence values for   | 
                            
read(integer  $length) : string
                Read data from the stream.
| integer | $length | Read up to $length bytes from the object and return them. Fewer than $length bytes may be returned if underlying stream call returns fewer bytes.  | 
                            
Returns the data read from the stream, or an empty string if no bytes are available.
getMetadata(string  $key = null) : array|mixed|null
                Get stream metadata as an associative array or retrieve a specific key.
The keys returned are identical to the keys returned from PHP's stream_get_meta_data() function.
| string | $key | Specific metadata to retrieve.  | 
                            
Returns an associative array if no key is provided. Returns a specific key value if a key is provided and the value is found, or null if the key is not found.