public long getExtentStartBlockNumber() {
		return Short.toUnsignedLong(ee_start_hi) << 32 | Integer.toUnsignedLong(ee_start_lo);
	}
Returns the block number of where the data for this extent is stored.

@return starting block number of where data for this extent is stored
Ghidra/Features/FileFormats/src/main/java/ghidra/file/formats/ext4/Ext4Extent.java