Function decode_source_block 

pub fn decode_source_block(
    encoding_symbols: &[Option<Vec<u8>>],
    nb_source_symbols: usize,
    source_block_length: usize,
) -> Option<Vec<u8>>

Decodes a source block from a given set of available encoding symbols.

Parameters

• encoding_symbols: A list of available encoding symbols. Missing encoding symbols should be represented as None.
• nb_source_symbols: The number of source symbols in the block (k).
• source_block_length: The size of the source block in bytes.

Returns

A vector of bytes representing the decoded source block, or None if the source block cannot be decoded. The function uses the available encoding symbols to reconstruct the original source block.