@Mr00Anderson ca. == approximately  . So yep PRs welcome 
Typo Documentation - MessageSizeEstimator.class
https://github.com/netty/netty/blob/00afb19d7a37de21b35ce4f6cb3fa7f74809f2ab/transport/src/main/java/io/netty/channel/MessageSizeEstimator.java#L19

"Responsible to estimate size of a message. The size represent how much memory the message will ca. reserve in memory."

I was going through the source and trying to determine where MessageSizeEstimator.class is used and what "ca" in the documentation means. I will make the pull request once I know what "ca" means, if it needs to be corrected.



transport/src/main/java/io/netty/channel/MessageSizeEstimator.java
transport/src/main/java/io/netty/channel/MessageSizeEstimator.java
diff --git a/transport/src/main/java/io/netty/channel/MessageSizeEstimator.java b/transport/src/main/java/io/netty/channel/MessageSizeEstimator.java
index 5c84927781a..92f164dc5d5 100644
--- a/transport/src/main/java/io/netty/channel/MessageSizeEstimator.java
+++ b/transport/src/main/java/io/netty/channel/MessageSizeEstimator.java
@@ -16,8 +16,8 @@
 package io.netty.channel;
 
 /**
- * Responsible to estimate size of a message. The size represent how much memory the message will ca. reserve in
- * memory.
+ * Responsible to estimate the size of a message. The size represents approximately how much memory the message will
+ * reserve in memory.
  */
 public interface MessageSizeEstimator {
 
