Table Block
Assessment API/Blocks

Unrolled Loop mode
Time rewinder
Tooltips over errors
Multiple block levels by manipulating the paths in the block.js file
    Remove color, reduce padding, simplify text
    Swap append order
    Drop "set" from assignment
    Add colons onto the end of lines
    create empty list becomes []
Add in variable dictionary access block
Tabular block
Call friend
    Identifies students in the cohort who are on the same problem
    Signals to the TA that the student has an issue
    Emails a question to the TA
Popup question dialog
    Fill in the blank
    Multiple choice
        What variable is a dictionary (selectable list of variables) - optionally show type.
    TAs see answers to questions

If then else - logic for instructor API
    Allowed to write python snippets
    Should the whole thing translate to python?

Turn off name wrangler? It might be better to let them make mistakes and then point them out.
Highlight parser error line in the code block!

Instead of having it shown as a value changing, visualize it as a cursor moving through list
    Integrate with JSAV
Predict the next value of the trace
Explain a given line of code
"All the variables you need are here" <-- prevent them from creating new variables.

Slowmode - when you run, it executes the code but "plays" its results slightly slowed down, so you can see the code highlighting.

Multiple levels of blocks (Block sets)

URL shortened forms

NameError
    Have they defined the variable after use? (differentiate between an update and an initialization)
        Line X attempts to use the variable <A> before it is declared. You have a declaration on Line Y. However, remember that your program executes top-to-bottom.
        
        If line X and line Y are equal
            Line X attempts to update the variable <A> with itself. You must initialize a variable before you can update it. Remember that the RIGHT-side of assignment statements are evaluate BEFORE the LEFT-side.
        
        Check to see if the usage is within a loop
            
    Have they possibly typo'd it?
        You attempted to use a variable <A> on line X. You have not declared a variable with that name. However, there is an <integer> variable named <A'>.
        
    Is there just nothing about it anywhere?
        You attempted to use the variable <A> before it is declared. Currently, you have not declared the variable anywhere. Remember that your program executes top-to-bottom.
        
TypeError
    Addition/Subtraction between list and number
    Addition/Subtraction between string and number
    Iterating over integer
        
    
ZeroDivisionError
    This error occurs because you attempted to divide by zero.
    It looks like you are using an empty list 
    

Using color heatmaps to teach students about iteration and decision- can we demonstrate how some code paths are explored more often? 

Color code (site creations) and (site overwrites)

For testing:
airlines.get_all(testing=True)

For production:
airlines.get_all()