private Address createExtendedLength(Address addr) {
		/*
		 * If length == 0xfffffff, then next 8-bytes indicate the length of the CIE
		 * structure. (Not including the "Length" field itself)
		 * TODO - figure out if we need to set the length for this.
		 */
		if (intLength == -1) {
			hasExtLength = true;
			String comment = "(FDE) Extended Length";
			createAndCommentData(program, addr, new QWordDataType(), comment, CommentType.EOL);
			// prog.getMemory().getBytes(addr, extLength);
			addr = addr.add(QWORD_LEN);
			curSize += QWORD_LEN;
		}
		return addr;
	}
Creates a Frame Description Entry (FDE) at the address
specified.
<br>Note: This method must get called before any of the "get..." methods.

@param fdeBaseAddress Address where the FDE should be created.
@return a region descriptor which holds information about this FDE. Otherwise, null.
@throws MemoryAccessException if memory for the FDE or its associated data can't be accessed
@throws ExceptionHandlerFrameException if there is an error creating the FDE information.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/exceptionhandlers/gcc/structures/ehFrame/FrameDescriptionEntry.java